Heavy p-type doping of ZnSe thin films using Cu ₂Se in pulsed laser deposition

Undoped, Cu-doped, Se-enriched, and Cu ₂Se-doped ZnSe films have been grown on fused quartz substrates by pulsed laser deposition. While the other films are highly resistive, Cu ₂Se-doped ZnSe films are p-type conducting with hole concentrations of ∼1.1 × 10 ¹⁹ cm ^-3 and resistivities of ∼0.098 Ω cm (compared with previous reports of ∼1×10 ¹⁸ cm ^-3 and ∼0.75 Ω cm). The exceptional heavy p-type doping of ZnSe films can be attributed to substitution of Zn atoms with Cu while limiting selenium-vacancy-associated compensating defects with additional selenium. This work is of importance to solve doping difficulties and contact problems of wide-bandgap semiconductors.