Improvement of electric properties in transparent p-Li0.07Ni0.93O(111)/n-ZnO(112̄0) heterojunction with Mg1−xZnxO intermediate layer

• The crystallinity of a-plane ZnO could be improved by inserting a Zn(Mn,Na)O buffer.
• Mg1−xZnxO intermediate layer could promote the LiNiO/ZnO junction characteristics.
• A feasible p–n heterojunction based on the nonpolar ZnO is provided.

Transparent p-Li0.07Ni0.93O(111)/n  -ZnO(112¯0) heterojunctions with and without a Mg1−xZnxO (x=0.4) intermediate layer were fabricated on r-plane sapphire substrates by pulsed laser deposition (PLD). The crystallinity of a-plane pure ZnO has been improved and the defect-related luminescence was restrained by introducing a thin Mn–Na codoped ZnO layer prior to the pure ZnO deposition. Both the heterojunctions show obvious rectifying properties and the introduction of Mg1−xZnxO layer facilitates the reduction in leakage current and shows improvement in junction characteristics. This work provides a feasible heterostructure based on the nonpolar ZnO which can potentially be used in the ZnO ultraviolet light-emitting or detecting devices.