Santana Guillermo, de Melo Osvaldo, Aguilar-Hernández Jorge, Mendoza-Pérez Rogelio, Monroy B Marel, Escamilla-Esquivel Adolfo, López-López Máximo, de Moure Francisco, Hernández Luis A, Contreras-Puente Gerardo
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Coyoacán, México DF, C.P. 04510, Mexico.
Escuela Superior de Física y Matemáticas del IPN, Edif. 9, Unidad Profesional Adolfo López Mateos, Col. Lindavista, México DF, C.P. 07738, Mexico.
Materials (Basel). 2013 Mar 15;6(3):1050-1060. doi: 10.3390/ma6031050.
Photoluminescence (PL) studies in GaN thin films grown by infrared close space vapor transport (CSVT-IR) in vacuum are presented in this work. The growth of GaN thin films was done on a variety of substrates like silicon, sapphire and fused silica. Room temperature PL spectra of all the GaN films show near band-edge emission (NBE) and a broad blue and green luminescence (BL, GL), which can be seen with the naked eye in a bright room. The sample grown by infrared CSVT on the silicon substrate shows several emission peaks from 2.4 to 3.22 eV with a pronounced red shift with respect to the band gap energy. The sample grown on sapphire shows strong and broad ultraviolet emission peaks (UVL) centered at 3.19 eV and it exhibits a red shift of NBE. The PL spectrum of GaN films deposited on fused silica exhibited a unique and strong blue-green emission peak centered at 2.38 eV. The presence of yellow and green luminescence in all samples is related to native defects in the structure such as dislocations in GaN and/or the presence of amorphous phases. We analyze the material quality that can be obtained by CSVT-IR in vacuum, which is a high yield technique with simple equipment set-up, in terms of the PL results obtained in each case.
本文介绍了通过真空红外近距离空间气相传输（CSVT-IR）生长的GaN薄膜的光致发光（PL）研究。GaN薄膜在多种衬底上生长，如硅、蓝宝石和熔融石英。所有GaN薄膜的室温PL光谱均显示出近带边发射（NBE）以及宽的蓝绿色发光（BL、GL），在明亮的房间里肉眼可见。在硅衬底上通过红外CSVT生长的样品显示出从2.4到3.22 eV的几个发射峰，相对于带隙能量有明显的红移。在蓝宝石上生长的样品显示出以3.19 eV为中心的强而宽的紫外发射峰（UVL），并且其NBE呈现红移。沉积在熔融石英上的GaN薄膜的PL光谱表现出以2.38 eV为中心的独特且强的蓝绿色发射峰。所有样品中黄色和绿色发光的存在与结构中的固有缺陷有关，如GaN中的位错和/或非晶相的存在。我们根据每种情况下获得的PL结果，分析了通过真空CSVT-IR可获得的材料质量，这是一种设备设置简单的高产技术。
