Modeling of the impact of Se-vacancies on the electrical properties of Cu(In,Ga)Se2 films and junctions

Autor: P. Zabierowski, Marek Maciaszek, Koen Decock
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Thin Solid Films
ISSN: 0040-6090
DOI: 10.1016/j.tsf.2013.01.035
Popis: In this contribution we aim at a better understanding the influence of metastable VSe defects on electrical characteristics of Cu(In,Ga)Se2-based solar cells. In order to achieve this goal we calculate the distribution of VSe charge states by solving numerically the equations involving transition rates between the metastable donor and acceptor configuration. By varying systematically the set of three parameters in a broad range (net shallow acceptor doping level, VSe defect density and temperature) we analyze quantitatively in which conditions and how the metastable defects influence/control the Fermi level position and hence the free carrier concentration. Using these results, we calculate time constants for conversion processes between donor and acceptor configurations. In the second part of the paper we model the influence of VSe-related defects on capacitance–voltage (CV) space charge profiles in different metastable states (reverse bias and light soaking). We propose a method allowing the evaluation of the lower bound for the metastable VSe defect concentration from CV profiles.
Databáze: OpenAIRE