Ga1-xAlxSb avalanche photodiodes: Resonant impact ionization with very high ratio of ionization coefficients
| Autor: | K.W. Benz, W. Kuebart, O. Hildebrand, M.H. Pilkuhn |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Physics
Avalanche diode business.industry Band gap Condensed Matter Physics Avalanche photodiode Threshold energy Atomic and Molecular Physics and Optics Avalanche breakdown Impact ionization Single-photon avalanche diode Ionization Optoelectronics Electrical and Electronic Engineering Atomic physics business |
| Zdroj: | IEEE Journal of Quantum Electronics. 17:284-288 |
| ISSN: | 0018-9197 |
| DOI: | 10.1109/jqe.1981.1071068 |
| Popis: | The liquid-phase epitaxy and device fabrication of p-n and p-i-n Ga 1-x Al x Sb avalanche photodiodes is described. Breakdown voltages up to 95 V and dark currents of 10-4A/cm2have been obtained. With p-i-n diodes we have measured the impact ionization coefficients α (electrons) and β (holes) with different composition and temperature. A resonant enhancement of the hole ionization coefficient is found for x = 0.065 (300 K) where the ratio \beta/\alpha exceeds values of 20. This effect is attributed to impact ionization initiated by holes from the split-off valence band: if the spin orbit splitting Δ is equal to the bandgap energy E g , the threshold energy for hole initiated impact ionization reaches the smallest possible value ( E_{i} = E_{g} ) and the ionization process occurs with zero momentum. This leads to a strong increase of β at \Delta/E_{g} = 1 . The experimentally determined dependence of ionization coefficients on threshold energy is compared with theoretical expectations. |
| Databáze: | OpenAIRE |
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