Effect of Milling Time, Doping Concentration and Temperature on the Structural, Microstructural and Optical Properties of Cu Doped ZnO Nanoceramics

In this work, high energy ball milling (HEBM) technique has been employed to successfully synthesize a series of Cu-doped ZnO nanoceramics (Zn 1-x Cu x O) with Cu concentration x = 0, 0.01, 0.02, 0.03 and 0.04. The synthesized nanoceramic was analysed by XRD, FESEM, TEM, Uv-Vis-DRS. The structural, microstructural and optical properties of the synthesized sample with different duration of milling, doping concentration and temperature has been investigated. X-ray diffraction result indicates that the samples are wurtzite structure with single phase. A decrease in peak intensity was observed with increase in milling time. 10h milled Cu doped ZnO sample shows single phase. After calcination at 900 ºC in x = 0.04 few peaks related to CuO was observed indicating the solubility limit of Cu in ZnO is 3 atomic%. With increase in milling time crystallite decreases where as strain increases however after calcination crystallite increases where as strain decreases. After calcination peak intensity increases. The specific surface area of ZnO increases after Cu doping but decreases after calcination. Bond length decreases after calcination but lattice distortion increases. FESEM micrograph shows particle growth after calcination. The average particle size decreases with increase in Cu concentration(30 nm to 20 nm) whereas increases after calcination and sintering (488 nm-2706 nm).The band gap decreases with increasing in milling time also with increase in Cu concentration and after calcination. Cu doping in ZnO shows red shift indicating Cu doped ZnO samples are suitable for optoelectronic device applications.