Copper alloyed ZnS was investigated as a p-type, transparent conducting material composed of earth-abundant elements. Thin films of Cu-alloyed ZnS were synthesized using pulsed laser deposition with Cu contents in the range of x = 0.06–0.27 (Cu content x is reported as the fraction of cation present). Thermopower and Hall effect measurements show that the films are p-type. We find that transparency and conductivity are comparable to some of the best reported p-type materials with our best films exhibiting conductivities of 54 S cm−1 and optical transmission of 65% at 550. The hole conduction mechanism is discussed in terms of possible Cu acceptor doping of the ZnS and hole conductivity in a minority Cu2S phase. Transparent rectifying p-CuZnS/n-ZnO diodes were fabricated.
Photo demonstrating the high transparency of a rectifying heterojunction diode made with p-type Cu-alloyed ZnS and n-type ZnO.