高抑制比背照式AlxGa1-xN pin日盲紫外探测器研究

Study on Back-illuminated AlxGa1-xN pin Solar-blind UV Photodetectors with High Rejection Ratio

摘要:

利用现有外延材料生长技术和器件工艺技术, 生长了背照式 Al_xGa_1-xN pin外延材料, 并用生长的材料制作了日盲紫外探测器, 测试结果表明器件在0V偏压下抑制比达到了6400。在此基础上, 较详细地分析了偏置电压、p- Al_xGa_1-xN载流子浓度和Al组分、极化效应对背照式 Al_xGa_1-xNpin日盲紫外探测器抑制比的影响及非日盲光生载流子的限制机制。分析表明, 提高p- Al_xGa_1-xN载流子浓度和GaN/ Al_xGa_1-xN异质结极化强度是现有技术条件下提高器件抑制比的有效途径。

Abstract:

In this paper, back-illuminated Al_xGa_1-xN-pin epitaxial materials were grown, and then solar-blind UV photodetectors with a high rejection ratio of up to 6400 tested under 0V bias were fabricated. The effects of bias voltage, the carrier concentration and Al component in p-Al_xGa_1-xN, and polarization effect on the rejection ratio of back-illuminated solar-blind UV photodetectors are analyzed in detail, and also the suppressing mechanisms of non-solar-blind photo-induced carriers are discussed. It is shown that increasing the carrier concentration in p-Al_xGa_1-xN and the polarization strength at p-GaN/p-Al_xGa_1-xN heterojunction are the most effective methods for enhancing the rejection ratio of photodetectors.