Solution-Processed Copper Selenium Oxide $(\text{CuSeO}_{3})$ as Hole Transport Layer for CdS/CdTe Solar Cells

Solution-processed Cu doping with Cu contained hole transport layer (HTL) in CdTe solar cells has attracted great attention due to its low cost, ease of process, low-temperature activation, and better Cu control advantages. Here, we introduced solution-processed copper selenate
$(\mathbf{CuSeO}_{3})$
as a Cu source and hole transport layer. Steady-state photoluminescence (PL) quenching effect and back-barrier height reduction together indicate efficient hole extraction from the bulk and suppressed carrier recombination at the back surface. As a result, a cell efficiency of 16.7
^%
was demonstrated with a Voc of 0.861 V and a fill factor of 76.65%.