Donor and Acceptor Dynamics of Phosphorous Doped ZnO Nanorods with Stable p-Type Conduction: Photoluminescence and Junction Characteristics

We employed temperature-dependent photoluminescence (PL) to explain the donor and acceptor dynamics in phosphorus doped stable p-type P:ZnO nanorods. The room temperature PL revealed good crystalline and optical quality of P:ZnO nanorods. The 10 K PL spectrum exhibited a dominant acceptor bound exciton (A(0)X) or donor bound exciton ((DX)-X-0) emission corresponding to p- and n-type P:ZnO nanorods, respectively. The donor acceptor-pair (DAP) transitions exhibited different thermal dissociation energies for the p- and n-type P:ZnO nanorods, suggesting their different quenching channels. The quenching of the DAP transitions of the p-type ZnO:P nanorods was associated with the thermal dissociation of the DAP into free excitons, while the DAP transition of the n-type ZnO:P nanorods was quenched through the thermal dissociation of the shallow donor into free electrons. The rectifying behavior of a p-n homojunction diode formed by the p-type P:ZnO nanorods on n-type ZnO film confirmed the p-type conduction of the P:ZnO nanorods.