掺铒GaN薄膜的背散射沟道分析和光致发光研究

RBS/channeling study and photoluminscence properties of Er-implanted GaN

采用背散射 (RBS) 沟道 (channeling)分析和傅里叶变换红外光谱 (FT IR)研究了掺铒GaN薄膜的晶体结构和光致发光 (PL)特性 .背散射 沟道分析结果表明 :随退火温度的升高 ,薄膜中辐照损伤减少 ;但当退火温度达到1 0 0 0℃ ,薄膜中的缺陷又明显增加 .Er浓度随注入深度呈现高斯分布 .通过沿GaN的 <0 0 0 1 >轴方向的沟道分析 ,对于 90 0℃ ,30min退火的GaN :Er样品 ,Er在晶格中的替位率约 76 % .光谱研究表明 :随退火温度的升高 ,室温下样品的红外PL峰强度增加 ;但是当退火温度达到 1 0 0 0℃ ,样品的PL峰强度明显下降 ;测量温度从 1 5K变化到 30 0K时 ,样品 (90 0℃ ,30min退火的GaN :Er)的 1 540nm处PL温度猝灭为 30 % .

The Raman back scattering/channeling technique was used to analyze the damage recovery at different annealing temperatures and to determine the lattice location of the Er-implanted GaN samples. A better damage recovery was observed with increasing annealing temperature below 1000degreesC, but a complete recovery of the implantation damage cannot be achieved. For a sample annealed for at 900degreesC 30 min the Er and Ga angular scans across the <0001> axis was measured indicating that about 76% of Er ions occupies substitutional sites. Moreover, the photoluminscence (PL) properties of Er-implanted GaN thin films have been also studied. The experimental results indicate that those samples annealed at a higher temperature below 1000degreesC had a stronger 1539nm PL intensity. The thermal quenching of PL intensity for samples annealed at 900degreesC measured at temperatures from 15K to 300K is 30%.