Al and N codoped ZnO thin films were grown on n-Si (100) substrate by sputtering technique. Hall effect measurements of as-grown films exhibited n-type conduction, however 500°C Ar annealed codoped films showed p-type conductivity with a hole concentration of 9.9×10 16 cm −3 , resistivity of 15.95Ω-cm and hole mobility of 3.95cm 2 /Vs, respectively. Codoped ZnO thin films were found to be highly c-axis oriented with good crystal quality. A neutral acceptor-bound exciton and donor–acceptor-pair emissions that appeared at room temperature photoluminescence measurement verify p-type conduction in Al and N codoped ZnO film. The current–voltage characteristics of p–n heterojunction evidently showed a diode like rectifying behaviour.