Summary of the photovoltaic performances of the OSCs^a with Cu_xAl_1-xS_y films used as HTL.

HTL (40 nm)	V oc (V)	J sc (mA cm−2)	FF (%)	PCE (%)
0.2	0.535	−5.63	40.39	1.22
0.3	0.533	−7.46	37.93	1.51
0.5	0.585	−8.88	47.16	2.45
0.7	0.251	−6.68	60.82	1.02
0.9	0.215	−6.45	50.05	0.69
1	0.18	−6.45	61.95	0.72
Champion (CuAlS2)	0.596	−9.21	48.7	2.67

^aThere were eight cells for each device in this study. The errors of the PCEs were ±0.10%.