Environmental Engineering Reference
In-Depth Information
Chapter 11
Is Fermi-Level Pinning Affecting
GaAs-Based Solar Cells?
11.1 Introduction
Fermi-levelpinningatfivediscretelevelsatmetal/n-CdTeinterfaces
sheds light on new understanding of the CdS/CdTe solar cells. This
wasmadepossiblepurelybythecarefulobservationofexperimental
results. The appearance of discrete potential barriers and well-
definedgroupsofopencircuitvoltagesarethekeyobservationsthat
led to the new understanding. These results were first published
in 2002 for CdS/CdTe solar cells [1], and a similar behaviour for
CIGS solar cells was revealed in 2009 [2]. This short chapter briefly
examines the experimental results emerging for GaAs-based solar
cells to date.
11.2 Observation of Discrete Sets of I-V Characteristics
Experimental results presented in chapters 7, 8, and 9 indicate that
solar cell devices or rectifying device structures based on GaAs
also show different potential barriers and, hence, different groups
