用于氮化镓发光二极管窗口层的铝掺杂氧化锌的生长(英文)

Growth of Al-doped ZnO Window Layer for GaN LED Application

因应新时代电子产品的需求，透明导电薄膜（Transparent Conductive Oxides，TCO）的应用也更加广泛，传统上是使用氧化铟锡（Indium Tin Oxide，ITO）薄膜为透明导电薄膜，但其在高温应用上较不稳定并且易放出毒性，因此，铝掺杂氧化锌薄膜（ZnO：AI，AZO）有逐渐取代ITO的趋势。本论文将探讨掺杂不同铝含量的影响，并且就其光电特性加以说明，最后得到其光的透过率-85％、电阻率-7．3×10^-3Ω·cm以及面粗糙度-28nm的铝掺杂氧化锌薄膜，其具有表面粗化、电流分布层及窗口层的作用。并且将掺铝的氧化锌薄膜应用于氮化镓发光二极管上，以掺铝氧化锌微结构作为透明传导层的氮化镓发光二极管（λD=530nm，300×300μm）在20mA的工作电流下，其正向电压值为3．3V，输出功率达1．7mW，并且由光学显微镜图可以得知，小电流注下其电流分布均匀。若将AZO制作参数再作适当优化调整，取代ITO作为P型氮化镓上的透明传导层的可行性应该很高。

Effects of A1 doping on the morphology and structure of M-doped ZnO（AZO） were discussed. Analysis of AZO was carried out by scanning electron microscopy, photoluminescence and double-crystal X-ray diffraction. The diffraction peak position of the （002） plane was shifted to a lower angle with increasing A1 concentration. It was found that the UV emission peak of near band edge emission in PL has a blue-shift to a region of higher photon energy with increasing A1 concentration. The AZO epilayer was used as surface texturing, uniform current spreading, high transparent and thick window layer for achieving a highly efficient LED. AZO was deposited on the GaN-based LEDs as the transparent conducting layer. Light transmission above -85% in the wavelength ranging from 400 to 700 nm, and AZO resistivity and roughness of -7.3× 10^-3 Ω·cm and -28 nm were obtained, respectively. The OM image shows that the LED with an AZO layer can reach a uniform current spreading at a relatively low current intensity （-0.02 mA）.