SPLTRAK Abstract Submission
Measurement of Band Alignment between ZnO Based Front Emitters and CdCl2 Treated CdSeTe/CdTe Absorbers
Xiaolei Liu1, Luke Jones1, Luksa Kujovic1, Nicholas Hunwick1, Luis Infante-Ortega1, Michael Walls1, Tushar Shimpi2, Walajabad Sampath2, Kurt Barth2, Stephen Jones3, Ochai Oklobia3, Stuart Irvine3
1Loughborough University, Loughborough , United Kingdom
/2Colorado State University, Fort Collins, CO, United States
/3Swansea University, Swansea, United Kingdom

Thin film CdSeTe/CdTe solar cells have achieved > 22% record efficiency and generated solar electricity at a cost as low as 3 US cents per in large scale utilities. In this work, the use of ZnO based n-type emitters is considered with the aim of improving the thin film CdSeTe/CdTe photovoltaic device efficiency still further. The measured conduction band offsets (CBOs) between ZnO and CdSeTe are determined to be in the “cliff” conformation. These CBOs will be optimized to achieve a “spike” conformation by incorporating suitable dopants to achieve high device efficiency. This work identifies new pathways to highly efficient ZnO based n-type emitters for arsenic doped CdTe solar cells. In particular, we have identified Sn, Ce and Cs as suitable dopants to generate the preferred ‘spike’ in the band alignment between the emitter layer and the CdSeTe absorber. Suitably doped emitter layers will be used in device research to reduce the deficit in open circuit voltage.