GaN的宽带黄光发射研究

使用非线性最优化技术，用多个高斯函数叠加最优化拟合非掺杂GaN薄膜的宽的黄色发光带. 发现宽带黄色发光带可分解为三个高斯型谱的叠加. 表明宽的黄色发光带是由三个独立辐 射跃迁发射叠加而成. 使用一种新的吸收归一化光致发光激发谱直接测量出此三个独立发射 的初始态能级，发现三个独立发射具有相同的初始态和不同的末态，并对初、末态能级的起 源作出了合理的指派. 关键词：GaN薄膜吸收归一化光致发光激发谱宽带黄光发射

Studies of broadband yellow luminescence of GaN

The broadband yellow luminescence(BYL) of undoped GaN film is fitted optimally by the linear superposition of multiple Gaussian functions by using nonlinear optimization technique. It is found that the BYL may be divided into the three Gauss_type spectra. It shows for the first time that the BYL originates from the combination of three independent radiative transitions. The energy levels of the initial states of the three independent transitions are measured directly in experiment by means of a novel absorption_normalized photoluminescent excitation spectroscopy. It is found that the three independent transitions have the same initial state but different final states. The origins of the initial and final states are assigned reasonably.