Study of MgCl2 activation treatment on the defects of CdTe solar cells by capacitance-voltage, drive level capacitance profiling and admittance spectroscopy techniques

摘要

CdTe solar cells have recently reached its highest conversion efficiencies, comparable to CulnGaSe(2) and Si devices. One of the key factors for the success of these devices is the so-called "activation" treatment, which typically consists in depositing a CdCl2 film on the CdTe absorber layer and in a subsequent annealing in air or nitrogen atmosphere. Nevertheless CdCl2 is a carcinogenic and water-soluble compound; for this reason recent studies have found MgCl2 as a good alternative.