【摘要】 采用分子束外延(MBE)技术在蓝宝石衬底上依次生长n+GaN下电极层、i型AlxGa1-xN势垒层和n+GaN发射极层,并通过半导体微细加工技术,制作了AlGaN/GaN异质结单片集成紫外/红外双色探测器。该器件利用不同的探测机理,同时实现了红外光和紫外光探测,拓展了响应光谱的范围。红外光探测是通过AlGaN/GaN异质结界面自由电子吸收和功函数内部光致发射效应完成的,紫外光探测是通过AlxGa1-xN势垒层带间吸收完成的。对单元器件的暗电流特性、紫外及红外光谱特性进行了测试。测试结果表明,紫外响应截止波长356 nm,响应度180 mA/W,红外响应峰值波长14.5μm,响应度49 mA/W。更多还原

【Abstract】 Using molecular beam epitaxy( MBE) technology,the epitaxial layer structure was grown on sapphire substrate from bottom to top as following: n+doped GaN bottom contact,undoped AlxGa1-xN barrier layer,n-doped GaN emitter layer. By semiconductor microfabrication technique,the monolithically integrated ultraviolet /infrared( UV /IR) dual color photodetector with AlGaN /GaN heterojunction structure was realized. The device achieves dual-color detector using different detection mechanisms,and expands the responsible spectrum. The infrared response was due to the free carrier absorption in the AlxGa1-xN /GaN heterojunction and the internal photoemission over the work function at the emitter barrier interface. The ultraviolet response was due to inter-band absorption in the AlxGa1-xN barrier region while. The dark current and both the UV and IR spectrum characteristic of the unit structure of IR /UV dual-color photodetector were measured and analyzed. The test results show that the cutoff wavelength of the UV spectrum is 356 nm and the UV responsivity is 180 mA /W. The peak wavelength of the IR spectrum and the IR responsivity is 14. 5 μm and 49 mA /W,respectively.更多还原