The objective of the present study is to explore the non-linear behaviour of Ce-doped ZnO system. Undoped and Ce-doped ZnO nanoparticles of size ~23–70 nm were prepared by sol-gel co-precipitation approach. There was complete absence of Ce-containing phase until 3 at.% dopant. Band-gap decreased in a linear manner from 3.262 to 3.212 eV on doping with Ce. Emission peaks at 360 and 380 nm were observed in the PL spectra. However, at 7 at.% dopant, CeO₂ and Ce₂O₃ were observed. Interestingly, a significant increase in second harmonic generation (SHG) signal intensity of ~3.5 times was observed when the dopant concentration was increased from 3 to 7 at.% in ZnO nanoparticles. The SHG signal in doped-ZnO was governed by micro-strain such that it increased with decrease of micro-strain and vice-versa. The dependence of ZnO morphology and SHG intensity on Ce-dopant concentration in ZnO has potential for applications in bio-imaging and bio-sensing.

本研究的目的是探索掺Ce的ZnO系统的非线性行为。通过溶胶-凝胶共沉淀法制备了尺寸约23-70 nm的未掺杂和Ce掺杂的ZnO纳米粒子。直到3原子％的掺杂剂为止，完全没有含铈的相。掺杂铈后，带隙从3.262 eV线性降低。在PL光谱中观察到360和380nm处的发射峰。但是，掺杂量为7 at。％的CeO ₂和Ce ₂ O ₃被观察。有趣的是，当ZnO纳米颗粒中的掺杂物浓度从3 at。％增加到7 at。％时，观察到〜3.5倍的二次谐波生成（SHG）信号强度显着增加。掺杂ZnO中的SHG信号受微应变控制，因此随着微应变的减少而增加，反之亦然。ZnO的形态和SHG强度对ZnO中Ce掺杂浓度的依赖性在生物成像和生物传感中具有潜在的应用前景。