Influence of relaxation processes on the evaluation of the metastable defect density in Cu(In,Ga)Se2
| Autor: | M. Maciaszek, P. Zabierowski |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Ternary semiconductors Chemistry General Physics and Astronomy 02 engineering and technology Cooling rates 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Acceptor Capacitance Lower limit Cross section (physics) Metastability 0103 physical sciences Relaxation (physics) Atomic physics 0210 nano-technology |
| Zdroj: | Journal of Applied Physics. 119:215103 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4953145 |
| Popis: | In this contribution, we investigated by means of numerical simulations the influence of relaxation processes related to metastable defects on electrical characteristics of Cu(In,Ga)Se2. In particular, we analyzed the relaxation of a metastable state induced by illumination at a fixed temperature as well as the dependence of the hole concentration on the temperature during cooling. The knowledge of these two relaxation processes is crucial in the evaluation of the hole concentration in the relaxed state and after light soaking. We have shown that the distribution of the metastable defects can be considered frozen below 200 K. The hole capture cross section was estimated as ∼3 × 10−15 cm2. It was shown that the usually used cooling rates may lead to relevant changes of the hole concentration. We calculated the lower limit of the hole concentration after cooling, and we presented how it depends on densities of shallow acceptors and metastable defects. Moreover, we proposed a method which allows for the evaluation of shallow acceptor and metastable defect densities from two capacitance-voltage profiles measured in the relaxed and light soaking states. Finally, we indicated experimental conditions in which the influence of relaxation processes on the accuracy of this method is the smallest. |
| Databáze: | OpenAIRE |
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