壳层厚度调控对AgIn_(x)Ga_(1-x)S_(2)/AgGaS_(2)量子点发光性能的影响

Effect of Shell-thickness Regulation on Luminescence Performance of AgIn_(x)Ga_(1-x)S_(2)/AgGaS_(2)Quantum Dots

采用多次交替注入壳层前驱体工艺,成功制备了具有不同壳层厚度的环保型AgIn_(x)Ga_(1-x)S(2)/AgGaS_(2)(AIGS/AGS)量子点。利用透射电子显微镜和X射线衍射技术对量子点的形貌及晶体结构进行了详细的表征,通过吸收光谱和光致发光光谱系统地分析了AGS壳层厚度对AIGS/AGS量子点发光性能的影响。实验结果表明,适当增加AGS壳层可以有效增强量子点的带边发射,抑制其缺陷发射,并显著提高其发光稳定性。经优化,具有最佳壳层厚度(5层)的AIGS/AGS量子点呈现出532 nm的纯正绿色发光和33 nm的半高全宽(FWHM),光致发光效率(PLQY)达到45%。将其应用于量子点发光二极管(QLED)的制备,所得器件的最大亮度可达1518 cd/m^(2),外量子效率(EQE)为0.26%,显示出良好的应用潜力。

A series of AgIn_(x)Ga_(1-x)S_(2)/AgGaS_(2)(AIGS/AGS)quantum dots(QDs)with varying shell thicknesses were synthesized by employing a technique that involves multiple rounds of alternate shell precursor injection.Using trans⁃mission electron microscopy(TEM)and X-ray diffraction(XRD)techniques,the morphology and crystal structure of the quantum dots were characterized in detail.Further,by employing absorption spectroscopy and photolumines⁃cence(PL)spectroscopy,the impact of the AGS shell thickness on the luminescent properties of AIGS/AGS quan⁃tum dots was systematically analyzed.The experimental results indicate that appropriately increasing the AGS shell thickness enhances the band-edge emission of QDs,suppresses defect emission,and improves PL stability.Nota⁃bly,the AIGS/AGS QDs with an optimal AGS shell thickness of 5 layers exhibit a pure green emission at 532 nm,a full width at half maximum(FWHM)of 33 nm,and a PL quantum yield(QY)of 45%.In term of light-emitting di⁃ode(LED)applications,the device achieves a maximum brightness of 1518 cd/m²and an external quantum efficien⁃cy(EQE)of 0.26%,demonstrating excellent potential for practical applications.