The effect of surface recombination on current in AlxGa1−xAs heterojunctions

We show that the 2kT current in double‐heterostructure AlxGa1−xAs p‐n junctions is primarily due to surface recombination at the junction perimeter. The rate of surface recombination is evaluated by means of two luminescence experiments. Both experiments provide evidence that the rate of surface recombination increases with bias as exp(eV/2kT) and has the correct magnitude to account for the measured I‐V curves. It is shown theoretically that recombination at a depleted surface is proportional to exp(eV/2kT) at high bias. The 2kT behavior is a consequence of the nearly constant ratio of electron and hole densities at the surface. The nearly constant ratio is needed to maintain equality of surface and surface depletion layer charge. p‐n junction perimeters of cleaved, etched, and proton‐bombarded interfaces are evaluated and found to have similar rates of nonradiative recombination with the rate of surface recombination given by R=s0(np)1/2, where s0 is approximately 4×105 cm/sec.

[1]  T. Paoli,et al.  Derivative measurements of the current-voltage characteristics of double-heterostructure injection lasers , 1976 .

[2]  G. B. Stringfellow.  Effect of surface treatment on surface recombination velocity and diode leakage current in GaP , 1976 .

[3]  D. H. Mash,et al.  Light-emitting diodes , 1977, Nature.

[4]  R. Hall.  Electron-Hole Recombination in Germanium , 1952 .

[5]  C. Sah,et al.  Carrier Generation and Recombination in P-N Junctions and P-N Junction Characteristics , 1957, Proceedings of the IRE.

[6]  C. Bittmann,et al.  Surface effects of GaAs0·6P0·4 light emitting diodes , 1973 .

[7]  C. Henry,et al.  Nonradiative ’’large dark spots’’ in AlxGa1−xAs‐GaAs heterostructures , 1977 .

[8]  H. Casey,et al.  Electroluminescent shifting-peak spectra in GaAs with uniform excitation , 1973 .

[9]  GaAs double-heterostructure photodetectors , 1977 .

[10]  H. Grubin.  The physics of semiconductor devices , 1979, IEEE Journal of Quantum Electronics.

[11]  P. Asbeck.  Self‐absorption effects on the radiative lifetime in GaAs‐GaAlAs double heterostructures , 1977 .

[12]  A. Mircea,et al.  A study of electron traps in vapour-phase epitaxial GaAs , 1975 .

[13]  H. C. Casey,et al.  Evidence for low surface recombination velocity on n‐type InP , 1977 .

[14]  Y. Okinaka.  An Electrochemical Study of Electroless Gold‐Deposition Reaction , 1973 .

[15]  W. Read,et al.  Statistics of the Recombinations of Holes and Electrons , 1952 .

[16]  H. Gatos,et al.  Observation of surface recombination variations in GaAs surfaces , 1977 .

[17]  J. Ralston.  Detailed light‐current‐voltage analysis of GaP electroluminescent diodes , 1973 .

[18]  Chih-Tang Sah,et al.  Effect of surface recombination and channel on P-N junction and transistor characteristics , 1962, IRE Transactions on Electron Devices.

[19]  R. N. Hall,et al.  Power Rectifiers and Transistors , 1952, Proceedings of the IRE.

[20]  F. Stern.  Self-Consistent Results for n -Type Si Inversion Layers , 1972 .

[21]  H. Casey,et al.  Concentration‐dependent absorption and spontaneous emission of heavily doped GaAs , 1976 .

[22]  R. Logan,et al.  Integrated GaAs-Al x Ga 1-x As double-heterostructure laser with independently controlled optical output divergence , 1975 .

[23]  C. Henry,et al.  Origin of n≃2 injection current in AlxGa1−xAs heterojunctions , 1977 .