A. Niemer, R. Pankrath, K. Betzler, M. Burianek, M. Mühlberg:
Dielectric properties and the phase transition of pure and cerium doped calcium-barium-niobate.
World Journal of Concensed Matter Physics 2(2):80-84 (2012), DOI: 10.4236/wjcmp.2012.22014 Abstract >>>

B. Andriyevsky, K. Doll, G. Cakmak, M. Jansen, A. Niemer, K. Betzler:
DFT-based ab initio study of structural and electronic properties of lithium fluorooxoborate LiB₆O₉F and experimentally observed second harmonic generation.
Phys. Rev. B 84:125112 (2011), DOI: 10.1103/PhysRevB.84.125112 Abstract >>>

Urs Heine, Klaus Betzler, Manfred Burianek, Manfred Mühlberg:
The temperature dependence of the band edge energy in calcium barium niobate.
Phys. Status Solidi RRL 4:166-168 (2010), DOI: 10.1002/pssr.201004158 Abstract >>>

Uwe Voelker, Kai Dinges, Urs Heine, Klaus Betzler:
Lengths of ferroelectric domains: the role of defects and random fields.
Phys. Rev. B 81:214104 (2010), DOI: 10.1103/PhysRevB.81.214104 Abstract >>>

Isabella-Ioana Oprea, Uwe Voelker, Alexander Niemer, Rainer Pankrath, Sergey Podlozhenov, Klaus Betzler:
Influence of erbium doping on phase transition and optical properties of strontium barium niobate.
Optical Materials 32:30-34 (2009), DOI: 10.1016/j.optmat.2009.05.015 Abstract >>>

Urs Heine, Uwe Voelker, Klaus Betzler, Manfred Burianek, Manfred Muehlberg:
The ferroelectric phase transition of calcium barium niobate: experimental evidence of Smolenskii’s model for diffuse phase transitions?.
New Journal of Physics 11:083021 (2009), DOI: 10.1088/1367-2630/11/8/083021 Abstract >>>

Ä. Andresen, A.-N. Bahar, D. Conradi, I.-I. Oprea, R. Pankrath, U. Voelker, K. Betzler, M. Wöhlecke, U. Caldiño, E. Martín, D. Jaque and J. García Solé:
Spectroscopy of Eu³⁺ ions in congruent strontium barium niobate crystals.
Phys. Rev. B 77:214102 (2008), DOI: 10.1103/PhysRevB.77.214102 Abstract >>>

C. David, A. Tunyagi, K. Betzler and M. Wöhlecke:
Compositional dependence of optical and vibrational properties of Strontium-Barium-Niobate (Sr_xBa_1-xNb₂O₆).
phys. stat. sol. (b) 244:2127-2137 (2007), DOI: 10.1002/pssb.200642370 Abstract >>>

Kunpeng Wang, Yuchen Ma, Klaus Betzler:
Defect-induced spin deterioration of La[sub 0.64]Sr[sub 0.36]MnO[sub 3]: Ab initio study.
Physical Review B (Condensed Matter and Materials Physics) 76:144431 (2007), DOI: 10.1103/PhysRevB.76.144431 Abstract >>>

Uwe Voelker, Urs Heine, Christoph Gödecker, Klaus Betzler:
Domain size effects in a uniaxial ferroelectric relaxor system: The case of Sr_xBa_1-xNb₂O₆.
Journal of Applied Physics 102:114112 (2007), DOI: 10.1063/1.2821754 Abstract >>>

Uwe Voelker and Klaus Betzler:
Domain morphology from k-space spectroscopy of ferroelectric crystals.
Phys. Rev. B 74:132104 (2006), DOI: 10.1103/PhysRevB.74.132104 Abstract >>>

Isabella-Ioana Oprea, Hartmut Hesse, and Klaus Betzler:
Luminescence of erbium-doped bismuth-borate glasses.
Opt. Mater. 28:1136-1142 (2006), DOI: 10.1016/j.optmat.2005.07.004 Abstract >>>

Sergey Podlozhenov, Heribert A. Graetsch, Julius Schneider, Michael Ulex, Manfred Wöhlecke and Klaus Betzler:
Structure of strontium barium niobate Sr_xBa_1-xNb₂O₆ (SBN) in the composition range 0.32 < x < 0.82.
Acta Cryst. B 62:960--965 (2006), DOI: 10.1107/S0108768106038869 Abstract >>>

Isabella-Ioana Oprea, Hartmut Hesse, and Klaus Betzler:
Infrared-to-visible upconversion luminescence in neodymium-doped bismuth-borate glass.
phys. stat. sol. (b) 242:R109 (2005), DOI: 10.1002/pssb.200541197 Abstract >>>

T. Volk, D. Isakov, N. Ivanov, L. Ivleva, K. Betzler, A. Tunyagi, and M. Wöhlecke:
Study of ferroelectric domain switching by domain-wall induced light scattering.
J. Appl. Phys. 97:074102 (2005), DOI: 10.1063/1.1882772 Abstract >>>

D. Xue, K. Betzler, H. Hesse, K. Kitamura, H. Ratajczak and J. Wang:
Search for new optical crystals by the chemical bond method.
J. Synthetic Crystals 33:605-612 (2004), Abstract >>>

D. Isakov, T. Volk, L. Ivleva, K. Betzler, C. David, A. Tunyagi and M. Wöhlecke:
Study of ferroelectric domain switching by domain-wall induced light scattering.
ZhETP-Letters 80:289 (2004), Abstract >>>

Michael Ulex, Rainer Pankrath, Klaus Betzler:
Growth of strontium barium niobate: the liquidus-solidus phase diagram.
J. Crystal Growth 271:128 (2004), DOI: 10.1016/j.jcrysgro.2004.07.039 Abstract >>>

Isabella-Ioana Oprea, Hartmut Hesse, Klaus Betzler:
Optical properties of bismuth borate glasses.
Opt. Mat. 26:235 (2004), DOI: 10.1016/j.optmat.2003.10.006 Abstract >>>

C. David, T. Granzow, A. Tunyagi, M. Wöhlecke, Th. Woike, K. Betzler, M. Ulex, M. Imlau, and R. Pankrath:
Composition dependence of the phase transition temperature in Sr_xBa_1-xNb₂O₆.
phys. stat. sol. (a) 201:R49 (2004), DOI: 10.1002/pssa.200409044 Abstract >>>

C. David, A. Tunyagi, M. Ulex, M. Wöhlecke, K. Betzler, K. Lengyel, L. Kovács:
Structure of the OH^- stretching vibrational band in Sr_xBa_1-xNb₂O₆.
J. Appl. Phys. 95:5522 (2004), DOI: 10.1063/1.1712011 Abstract >>>

C. Bäumer, C. David, K. Betzler, H. Hesse, K. Lengyel, L. Kovács, M. Wöhlecke:
Composition Dependence of the OH-Stretch-Mode Spectrum in Lithium Tantalate.
phys. stat. sol. (a) 201:R13 (2004), DOI: 10.1002/pssa.200409028 Abstract >>>

Arthur R. Tunyagi, Michael Ulex, Klaus Betzler:
Non-collinear optical frequency doubling in strontium barium niobate.
Phys. Rev. Lett. 90:243901 (2003), DOI: 10.1103/PhysRevLett.90.243901 Abstract >>>

Ch. Bäumer, C. David, A. Tunyagi, K. Betzler, H. Hesse, E. Krätzig, M. Wöhlecke:
Composition dependence of the ultraviolet absorption edge in lithium tantalate.
J. Appl. Phys. 93:3102 (2003), DOI: 10.1063/1.1542689 Abstract >>>

K.-U. Kasemir, K. Betzler:
Detecting ellipses of limited eccentricity in images with high noise levels.
Image and Vision Computing 21:221 (2003), Abstract >>>

D. Xue, K. Betzler, H. Hesse:
Chemical bond analysis of the nonlinear optical properties of the borate crystals LiB₃O₅, CsLiB₆O₁₀, and CsB₃O₅.
Applied Physics A 74:779 (2002), Abstract >>>

D.Xue, K. Betzler, H. Hesse, H. Ratajczak:
Chemical bond analysis on second order nonlinear optical properties of Na₂SeO₄^.H₂SeO₃^.H₂O.
Bulletin of the Polish Academy of Sciences-Chemistry 50:289 (2002), Abstract >>>

D.Xue, K. Betzler, H. Hesse, D. Lammers:
Linear and nonlinear optical susceptibilities of orthorhombic rare earth molybdates RE₂(MoO₄)₃.
J. Phys. Chem. Solids 63:359 (2002), Abstract >>>

D.Xue, K. Betzler, H. Hesse, H. Ratajczak:
Theoretical analysis of the chemical bonding behavior and the dielectric properties of different phases of ice.
Bulletin of the Polish Academy of Sciences-Chemistry 49:289 (2001), Abstract >>>

D.Xue, K. Betzler:
Influence of optical-damage resistant dopants on the nonlinear optical properties of lithium niobate.
Applied Physics B 72:641 (2001), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Induced Li-site vacancies and nonlinear optical behavior of doped lithium niobate crystals.
Optical Materials 16:381 (2001), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Second order nonlinear optical properties of In-doped lithium niobate.
J. Appl. Phys. 89:849 (2001), Abstract >>>

D.Xue, K. Betzler, H. Hesse, D. Lammers:
Temperature dependence of the dielectric response of lithium niobate.
J. Phys. Chem. Solids 62:973 (2001), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Dielectric properties of I-III-VI₂ type chalcopyrite semiconductors.
Physical Review B15 62:13546 (2000), Abstract >>>

D. Lammers, K. Betzler, D. Xue, J. Zhao:
Optical Second-Harmonic Generation in Benzophenone.
physica status solidi (a) 180:R5 (2000), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Chemical bond analysis of the second order nonlinear optical behavior of Zn-doped lithium niobate.
Optics Communications 182:167 (2000), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Dielectric properties of lithium niobate-tantalate crystals.
Solid State Communications 115:581 (2000), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Chemical bond analysis of the second order nonlinear optical behavior of Mg-doped lithium niobate.
J. Phys.: Condens. Matter 12:6245 (2000), Abstract >>>

D.Xue, K. Betzler, H. Hesse, D. Lammers:
Nonlinear optical properties of borate crystals.
Solid State Communications 114:21 (2000), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Dielectric constants of binary rare-earth compounds.
J. Phys.: Condens. Matter 12:3113 (2000), Abstract >>>

D.Xue, K. Betzler, H. Hesse:
Structural characteristics and second order nonlinear optical properties of borate crystals.
Trends in Optics and Photonics Series 34:542 (2000), Abstract >>>

D. Xue, K. Betzler, H. Hesse, D. Lammers, S. Zhang:
Theoretical studies of nonlinear optical properties of compounds K₄Ln₂(CO₃)₃F₄ (Ln=Pr, Nd, Sm, Eu, Gd).
J. Appl. Physics 87:2849 (2000), Abstract >>>

K. Betzler, H. Hesse, R. Jaquet, D. Lammers:
Optical second-harmonic generation in lead formate.
J. Appl. Physics 87:22 (2000), Abstract >>>

D. Xue, K. Betzler, H. Hesse, D. Lammers:
Relationship between Dielectric Responses and Constituent Atoms in Crystal Materials.
physica status solidi (b) R7:216 (1999), Abstract >>>

D. Xue, K. Betzler, H. Hesse, D. Lammers:
Origin of the Large Nonlinear Optical Coefficients in Bismuth Borate BiB₃O₆.
physica status solidi (a) 176/2:R1 (1999), Abstract >>>

K.-U. Kasemir, K. Betzler:
Characterization of photorefractive materials by spontaneous noncolinear frequency doubling.
Applied Physics B 68:763 (1999), Abstract >>>

Chr. a. d. Horst, K.-U. Kasemir, K. Betzler:
Determination of Homogeneity of Pure and Doped Lithium Niobate by SHG Temperature Phase-Matching.
J. Appl. Physics 84:5158 (1998), Abstract >>>

K. Kasemir, K. Betzler, B. Matzas, B. Tiegel, T. Wahlbrink, M. Wöhlecke, B. Gather, N. Rubinina, T. Volk:
Influence of Zn/In Codoping on the Optical Properties of Lithium Niobate.
J. Appl. Physics 84:5191 (1998), Abstract >>>

K. Kasemir, K. Betzler, B. Matzas, B. Tiegel, M. Wöhlecke, N. Rubinina, T. Volk:
Influence of In Doping on the Refractive Indices of Lithium Niobate.
physica status solidi (a) 166/1:R7 (1998), Abstract >>>

K. Chah, M. Aillerie, M. D. Fontana, G. I. Malovichko, K. Betzler, E. Kokanyan:
Influence of chromium doping on the electro-optic properties of lithium niobate.
Optics Commun. 136:231 (1997), Abstract >>>

A. Reichert, K. U. Kasemir, K. Betzler:
Application of noncolinear frequency doubling for crystal characterization.
Materials Science Forum 239-241:329 (1997), Abstract >>>

M. Wöhlecke, G. Corradi, K. Betzler:
Optical Methods to Characterise the Composition and Homogeneity of Lithium Niobate Single Crystals.
Applied Physics B 63:323 (1996), Abstract >>>

A. Reichert, K. Betzler:
Induced noncolinear frequency doubling: A new characterization technique for electrooptic crystals.
J. Appl. Phys. 79:2209 (1996), Abstract >>>

U. Schlarb, B. Matzas, A. Reichert, K. Betzler, M. Wöhlecke, B. Gather, T. Volk:
Refractive indices of Zn/In-co-doped lithium niobate.
Ferroelectrics 185:269 (1996), Abstract >>>

A. Reichert, K. U. Kasemir, K. Betzler:
Crystal characterization by noncolinear frequency doubling.
Ferroelectrics 184:21 (1996), Abstract >>>

T. Volk, M. Wöhlecke, N. Rubinina, A. Reichert, and N. Razumovski:
Optical-damage-resistant impurities (Mg, Zn, In, Sc) in lithium niobate.
Ferroelectrics 183:291 (1996), Abstract >>>

U. Schlarb, A. Reichert, K. Betzler, M. Wöhlecke, B. Gather, T. Volk, N. Rubinina:
SHG phase matching conditions for undoped and doped lithium niobate.
Rad. Effects and Defects in Solids 136(1-4):1029 (1995), Abstract >>>

U. Schlarb, M. Wöhlecke, B. Gather, A. Reichert, K. Betzler, T. Volk, N. Rubinina:
Refractive indices of Zn-doped lithium niobate.
Optical Materials 4:791 (1995), Abstract >>>

T. Volk, M. Wöhlecke, A. Reichert, F. Jermann, and N. Rubinina:
The peculiar impurity concentration ranges in damage resistant LiNbO₃ crystals doped with Mg, Zn, In, and Sc.
Ferroelectrics Letters 20:97 (1995), Abstract >>>

F. Kahmann, A. Reichert, K. Lytze, R. Blachnik, K. Betzler, R. Rupp:
Photorefractive effect in Cd₁₃P₄S₂₂I₂.
Phys. Rev. B 52:870 (1995), Abstract >>>

U. Schlarb, K. Betzler:
Influence of the defect structure on the refractive indices of undoped and Mg-doped lithium niobate.
Phys. Rev. B 50:751 (1994), Abstract >>>

U. Schlarb, B. Sugg:
Refractive index of terbium gallium garnet.
Phys. stat. sol. (b) 182:K91 (1994), Abstract >>>

U. Schlarb, K. Betzler:
A generalized Sellmeier equation for the refractive indices of lithium niobate.
Ferroelectrics 156:99 (1994), Abstract >>>

A. Reichert, K. Betzler:
Non-colinear frequency doubling in lithium niobate.
Ferroelectrics 156:93 (1994), Abstract >>>

U. Schlarb and K. Betzler:
Refractive indices of lithium niobate as a function of temperature, wavelength, and composition: A generalized fit.
Phys. Rev. B 48:15613 (1993), Abstract >>>

U. Schlarb, S. Klauer, M. Wesselmann, K. Betzler and M. Wöhlecke:
Determination of the Li/Nb Ratio in Lithium Niobate by Means of Birefringence and Raman Measurements.
Appl. Phys. A 56:311 (1993), Abstract >>>

U. Schlarb and K. Betzler:
Refractive indices of lithium niobate as a function of wavelength and composition.
J. Appl. Phys. 73:3472 (1993), Abstract >>>

G. I. Malovichko, V. G. Grachev, E. P. Kokanyan, O. F. Schirmer, K. Betzler, B. Gather, F. Jermann, S. Klauer, U. Schlarb, and M. Wöhlecke:
Characterization of stoichiometric LiNbO₃ grown from melts containing K₂O.
Appl. Phys. A 56:103 (1993), Abstract >>>

U. Schlarb, K. Betzler:
Interferometric measurement of refractive indices of LiNbO₃.
Ferroelectrics 126:39 (1992), Abstract >>>

A. Reichert, K. Betzler:
Characterization of electrooptic crystals by non-collinear frequency doubling.
Ferroelectrics 126:9 (1992), Abstract >>>

N. Schmidt, P. Voigt, B. Hellermann, K. Betzler, H. Hesse, S. Kapphan:
Phase matching for second harmonic generation in KNbO₃:Ta crystals with Nd:YAG- and GaAs-laser wavelengths.
Journal of Applied Physics 69:3426 (1991), Abstract >>>

N. Schmidt, P. Voigt, B. Hellermann, K. Betzler, H. Hesse, S. Kapphan:
Frequency doubling of YAG- and GaAs-lasers by KNbO₃:Ta crystals.
Radiation Effects and Defects in Solids 119-121:281 (1991), Abstract >>>

N. Schmidt, K. Betzler, B. C. Grabmaier:
Composition dependence of the second-harmonic phase-matching temperature in LiNbO₃.
Applied Physics Letters 58:34 (1991), Abstract >>>

P. Voigt, K. Betzler, N. Schmidt, S. Kapphan:
Second harmonic generation study of field-induced changes in the phase transition of K_1-xLi_xTaO₃.
Ferroelectrics 106:149 (1990), Abstract >>>

N. Schmidt, K. Betzler, M. Grabs, S. Kapphan, F. Klose :
Spatially resolved second-harmonic generation investigations of proton-induced refractive index changes in LiNbO₃.
J. Appl. Phys. 65:1253 (1989), DOI: 10.1063/1.343018 Abstract >>>

K. Betzler, A. Gröne, N. Schmidt, P. Voigt :
Interferometric measurement of refractive indices.
Rev. Sci. Instr. 59:652 (1988), DOI: 10.1063/1.1139853 Abstract >>>

K. Betzler, B. Hellermann, H. Hesse :
Influence of the dielectric constant anisotropy on the poling of ferroelectrics .
Ferroelectrics Letters 7:143 (1987), DOI: 10.1080/07315178708200543 Abstract >>>

N. Schmidt, K. Betzler, S. Kapphan:
Spatially resolved second harmonic generation and interferometric investigations of LiNbO₃ crystals.
Cryst. Latt. Def. and Amorph. Mat. 15:103 (1987), Abstract >>>

M. Grabs, K. Betzler, S. Kapphan:
Optical second harmonic measurements on KTaO₃:Li .
Ferroelectrics Letters 2:41 (1984), DOI: 10.1080/07315178408202432 Abstract >>>

L. Schüler, K. Betzler, H. Hesse, S. Kapphan:
Phase-matched second harmonic generation in potassium malate.
Opt. Commun. 43:157 (1982), DOI: 10.1016/0030-4018(82)90112-2 Abstract >>>

K. Betzler:
Second harmonic generation near the phase transition of SrTiO₃.
Ferroelectrics 26:819 (1980), DOI: 10.1080/00150198008008179 Abstract >>>

K. Betzler, D. Bäuerle:
Second-harmonic generation in “Cubic” PLZT ceramics.
Appl. Phys. A 18:271 (1979), DOI: 10.1007/BF00885513 Abstract >>>

K. Betzler, D. Bäuerle:
Second harmonic generation in squaric acid.
Phys. Letters A 70:153 (1979), DOI: 10.1016/0375-9601(79)90054-9 Abstract >>>

K. Betzler, H. Hesse, P. Loose:
Optical second harmonic generation in organic crystals: urea and ammonium-malate.
J. Molecular Structure 47:393 (1978), DOI: 10.1016/0022-2860(78)87207-X Abstract >>>

P. Loose, K. Betzler, D. Bäuerle, S. Kapphan:
Rayleigh scattering near the paraelectric-ferroelectric phase transition in BaTiO₃.
Proc. Int. Conf. Lattice Dynamics, Flammarion :681 (1978), Abstract >>>

K. Betzler, H. Hesse, P. Loose:
Optical second harmonic generation in ammonium malate.
Opt. Commun. 22:66 (1977), DOI: 10.1016/0030-4018(77)90248-6 Abstract >>>

D. Bäuerle, K. Betzler, H. Hesse, S. Kapphan, P. Loose:
Phase-matched second harmonic generation in urea.
phys. stat. sol. (a) 43:K119 (1977), DOI: 10.1002/pssa.2210420254 Abstract >>>

A. L. Karuzskii, K. Betzler, B. G. Zhurkin,W. P. Aksenov:
Magnetooscillations of the EHD luminescence in As-doped Ge.
Molecular spectroscopy of dense phases, Elsevier Amsterdam :139 (1976), Abstract >>>

K. Betzler, B. G. Zhurkin, A. L. Karuzskii, B. M. Balter:
Magnetooscillations of the electron-hole drop luminescence in germanium.
J. Luminescence 12-13:651 (1976), DOI: 10.1016/0022-2313(76)90156-3 Abstract >>>

Klaus Betzler:
Auger recombination in the electron-hole drops in Si and Ge .
Lecture Notes in Physics - Physics of Highly Excited States in Solids 57:211 (1976), DOI: 10.1007/3-540-07991-2 Abstract >>>

K. Betzler, B. G. Zhurkin, A. L. Karuzskii:
Magnetic-field dependent intensity oscillations of the EHD luminescence in pure germanium.
Sol. State Commun. 17:577 (1975), Abstract >>>

K. Betzler, R. Conradt:
Two-electron band to band transitions in silicon.
Sol. State Commun. 17:823 (1975), Abstract >>>

K. Betzler, B. G. Zhurkin, A. L. Karuzskii:
Magnetooscillations of the EHD TA-Line in Pure Germanium.
phys. stat. sol. (b) 70:K109 (1975), DOI:  10.1002/pssb.2220700247 Abstract >>>

K. Betzler, B. G. Zhurkin, A. L. Karuzskii:
Magnetic field dependent intensity oscillations of the EHD luminescence in pure germanium.
Series of Selected Papers in Physics: Electron-Hole Drops (Phys. Soc. Jap.) :108 (1975), Abstract >>>

A. L. Karuzskii, K. Betzler, B. G. Zhurkin, B. M. Balter:
Magnitnie oszilljazii poluschirini linii ljumineszenzii EDK w tschistom germanii.
Zh. Eks. Teor. Fis. 69:1088 (1975), Abstract >>>

A. L. Karuzskii, K. Betzler, B. G. Zhurkin,W. P. Aksenov:
Magnitnie oszilljazii ljumineszenzii elektronno-dirotschnich kapel w germanii c primes’ju misch’jaka.
Fiz. Tverd. Tela 17:3104 (1975), Abstract >>>

A. L. Karuzskii, K. Betzler, B. G. Zhurkin, B. M. Balter:
Magnitnie oszilljazii wremeni schisni elektronno-dirotschnich kapel w tschistom Ge.
Pis’ma w ZhETF 22:65 (1975), Abstract >>>

P. S. Gladkov, K. Betzler, B. G. Zhurkin, A. L. Karuzskii.:
Spektralnaja sawisimost magnitnich oszilljazii intensiwnosti ljumineszenzii EDK w tschistom Ge.
Zh. Eks. Teor. Fis. 69:2199 (1975), Abstract >>>

K. Betzler:
Relaxation of Auger-excited carriers in silicon.
Sol. State Commun. 15:1837 (1974), Abstract >>>

W. Zeh, K. Betzler, R. Conradt:
Two-electron transitions in germanium.
Sol. State Commun. 14:967 (1974), Abstract >>>

Klaus Betzler:
Untersuchung von Zwei-Elektronen-Rekombinations-Prozessen in Halbleitern mit indirekter Bandstruktur.
Dissertation Universität Stuttgart : (1974), Abstract >>>

K. Betzler, R. Conradt:
Two-electron transitions in germanium.
Sol. State Commun. 10:79 (1972), Abstract >>>

K. Betzler, R. Conradt:
Two-electron transitions in the condensed phase of nonequilibrium carriers in Si.
Phys. Rev. Lett. 28:1562 (1972), DOI: 10.1103/PhysRevLett.28.1562 Abstract >>>

K. Betzler, T. Weller, R. Conradt:
Two-Electron Band-to-Band Transitions in Solids.
Phys. Rev. B 6:1394 (1972), DOI: 10.1103/PhysRevB.6.1394
Abstract: In highly excited Si and Ge there appears an emission band at about h?=2Eg, which is explained by two-electron radiative transitions across the band gap. The dependence on energy, temperature, and excitation intensity is measured and compared with theoretical calculations. The weak temperature dependence, the quadratic dependence on the injection current, and the energy dependence agree with the theoretical consideration. A transition coefficient of about 10-61 cm9 sec-1 is found, in agreement with a rough theoretical estimate. The line shape indicates that, at least at room temperature, the two-electron transitions are phonon assisted. This leads also to the conclusion that the Auger recombination in Si must be phonon assisted, in contradiction to former considerations. (Close Abstract <<<)

K. Betzler, R. Conradt:
Radiative two-electron transitions in the electron-hole plasma in silicon at 2 K.
Proc. Int. Conf. Sem. Warsaw :684 (1972), Abstract >>>

K. Betzler, T. Weller, R. Conradt:
Improvement of photon counting by means of a pulse height analyzer.
Rev. Sci. Instr. 42:1594 (1971), Abstract >>>

K. Betzler, T. Weller, R. Conradt:
Experimental evidence of two-electron transitions in solids.
Phys. Rev. Lett. 26:640 (1971), DOI: 10.1103/PhysRevLett.26.640 Abstract >>>

Klaus Betzler:
Photonenemission oberhalb der Bandkante von Halbleitern.
Diplomarbeit Universität Stuttgart : (1971), Abstract >>>