High-Performance Long-Wavelength InAs/GaSb Superlattice Detectors Grown by MOCVD
High-Performance Long-Wavelength InAs/GaSb Superlattice Detectors Grown by MOCVD
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MOCVD 生长的高性能长波长 InAs/GaSb 超晶格探测器
DOI：
10.1109/lpt.2018.2889575
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发表时间：
2019
影响因子：
2.6
通讯作者：
Huang Yong
中科院分区：
文献类型：
--
作者：
Teng Yan;Zhao Yu;Wu Qihua;Li Xin;Hao Xiujun;Xiong Min;Huang Yong
基于金属有机化学气相沉积生长的无铝单异质结，研制了高性能的InAs/GaSb超晶格(SL)红外探测器。这些器件采用了中波长InAs/GaSb SL p-n结(PN)和长波长InAs/GaSb SL n型吸收体(N)，即所谓的PNN设计，以减少暗电流。此外，采用浅层腐蚀技术，在像素隔离过程中只曝光中波长材料，以抑制表面漏电流。在77K和−0.1V的偏置电压下，该器件在<；直列式公式>；<；tex数学记号=“Laex”>；$8.0MU\Text{m}$<；/特式公式>；，暗电流密度为<；直列式公式>；<；特数学记号=“乳胶”>；$2.4\x 10^{-5}$<；和2.1A/W的峰值响应率。随温度变化的暗电流测量表明，扩散限制行为低至75K。比探测率估计为<；内联公式=“Laex”>；$7.3\x 10^{11}\，\，\Text{cm}\CDOT\Text{Hz}^{1/2}/{\mathm{W}}$<；/Tex-ma>；/inline公式>；，可与类似截止波长的分子束外延生长的探测器相媲美。
We demonstrate the high-performance long-wavelength InAs/GaSb superlattice (SL) infrared photodetectors based on an Al-free single heterojunction grown by metalorganic chemical vapor deposition. The devices feature a mid-wavelength InAs/GaSb SL p-n junction (PN) and a long-wavelength InAs/GaSb SL n-type absorber (n), so-called PNn design, to reduce the dark current. In addition, a shallow-etch technique was employed by exposing only the mid-wavelength materials during pixel isolation to suppress the surface leakage currents. At 77 K and a bias voltage of −0.1 V, the device exhibited a 50% cutoff wavelength at <inline-formula> <tex-math notation="LaTeX">$8.0~\mu \text{m}$ </tex-math></inline-formula>, a dark current density of <inline-formula> <tex-math notation="LaTeX">$2.4\times 10^{-5}$ </tex-math></inline-formula> A/cm<sup>2</sup>, and a peak responsivity of 2.1 A/W. Temperature-dependent dark current measurement indicated the diffusion-limited behavior down to 75 K. The specific detectivity was estimated to be <inline-formula> <tex-math notation="LaTeX">$7.3\times 10^{11}\,\,\text {cm} \cdot \text {Hz}^{1/2}/{\mathrm{ W}}$ </tex-math></inline-formula>, which is comparable with that of detectors grown by the molecular beam epitaxy at similar cutoff wavelengths.