Role of oxygen during CdTe growth for CdTe photovoltaic devices

ABSTRACT Polycrystalline CdTe thin films for CdTe solar cell devices are typically grown using physical vapor techniques such as close‐spaced sublimation or vapor transport deposition with, in some cases, a small amount of oxygen in the process gas. In this report, we discuss the results of growing CdTe films in an environment of pure oxygen using close‐space sublimation. The results show that oxygen has a positive impact on CdTe film quality as it increases charge carrier mobility and lifetime in the absorber layer of CdTe‐based devices. This has resulted in a 10–20 mV improvement in open‐circuit voltages when growing the CdTe in pure oxygen. Copyright © 2014 John Wiley & Sons, Ltd. Adding oxygen to the CdTe growth process results in increased carrier lifetimes. This has resulted in a 10–20 mV improvement in open‐circuit voltages when growing the CdTe in pure oxygen, contributing to achieving 18.3% record cells in the end of 2012.