ZnMgO solid solutions system presents interest for optoelectronic application due to possibilities to tailor many important physical properties by varying their composition [1]. In this paper, we present data concerning responsivity and detectivity of Zn0.8Mg0.2O/p-Si photodetectors based on thin films prepared by spin-coating and aerosol deposition methods from 0.35 M aqueous solution using Zn and Mg acetates. The morphological and chemical composition of films has been investigated in details by scanning electron microscopy (SEM) and Energy Dispersive X-ray analysis (EDX). The photoelectrical parameters of detectors (Fig. 1) have been deduced from current-voltage characteristics measured in the dark and under UV illumination.figureFigure 1. The responsivity and detectivity under different bias voltage of ZnMgO/p-Si thin films The photocurrent was generated by a xenon DKSS-150 lamp using an optical filter (УФС5-300 nm). The responsivity (R) and detectivity (D*) under UV illumination of 63 mW/cm2 and 10 V direct bias were found to be of R = 0.38 A/W, D* = 2×1010 cm×Hz1/2W1 for films deposited by spin coating; and R = 0.264 A/W, D* = 9.7×109 cm×Hz1/2W-1 for films prepared by aerosol deposition.