Title | Effect of Close Space Sublimation Deposited CdS on the Performance and OBIC Response of CdTe Solar Cells |
Author(s) | Jonathan Major, Ken Durose |
Keywords | CdS, CdTe, Devices |
Topic | Thin Film Solar Cells |
Subtopic | CdTe Solar Cells |
Event | 25th EU PVSEC / WCPEC-5 |
Session | 3BV.2.114 |
Pages manuscript | 3476 - 3480 |
ISBN | 3-936338-26-4 |
DOI | 10.4229/25thEUPVSEC2010-3BV.2.114 |
The role of oxygen in close space sublimation (CSS) deposited CdS films upon the performance of CdTe/CdS solar cells was investigated. CdS films were deposited using a range of oxygen pressures, with the effect on device performance being assessed by J-V, external quantum efficiency and optical beam induced current (OBIC) analysis. By inclusion of increased quantities of oxygen into the CdS deposition ambient (0 - 4 Torr) the average device VOC was found to increase from 0.57 V to 0.67 V, whilst all other parameters showed no systematic variation. Multi-wavelength OBIC analysis of devices with CdS layers deposited under vacuum and oxygen (but otherwise similar), revealed those with oxygen to have a more uniform photovoltaic response. High resolution SEM analysis of CdS layers shows the range of CdS grain size achievable by CSS deposition. Further improvements to all-CSS deposited cells are reported with cell efficiencies of up to 11.65% being measured.