Abstract: ZnO has recently become a very popular material due to its great potential for
optoelectronics applications. To realize practical application of short-wavelength optoelectronic devices (such as LEDs and LDs) based on ZnO materials, electroluminescence (EL) from ZnO p-n homojunction is pivotal. In this article, ZnO homojunction was grown on single-crystal GaAs (100) substrate by ultrasonic spray pyrolysis with Zn(CH₃COO)_2^﹒2H₂O as precursor solution. CH₃COONH₄ and In(NO₃)₃ aqueous solutions were chosen as the doping sources of nitrogen and indium respectively. The ZnO homojunction was comprised of N-In codoped p-type ZnO and unintentionally doped n-type ZnO film. Ohmic contact layers on n-type ZnO layer and GaAs substrate were formed by Zn/Au and Au/Ge/Ni electrode respectively. Moreover, light emission was observed under forward current injection at room temperature, the emission could be clearly seen by the naked eye in a darkened room. With the demonstrated success of electroluminescence from ZnO p-n homojunction at room temperature, the application of short-wavelength optoelectronic devices based on ZnO materials should be possible in the near future.

Key words: ZnO film, p-n homojunction, electroluminescence, ultrasonic spray pyrolysis