The pursuit of optoelectronic devices operating in mid-infrared regime is driven by both fundamental interests and commercial applications. The narrow bandgap (0.3 eV) of layered Bi2Se3 makes it a promising material for mid-infrared photodetection. However, the weak absorption of mid-infrared optical power and high dark current level restrict its performance. Here, a supply-control technique is applied to modulate the growth mode of Bi2Se3 crystal, and Bi2Se3 crystals with various morphologies are obtained. The nanoplates pattern transits from maze to freestanding when source mass was tuned. Due to the strong infrared absorption and photoelectric conversion efficiency of vertical Bi2Se3 nanoplates, the as-prepared vertical Bi2Se3 nanoplates/Si heterojunction shows excellent photoresponse and extremely low dark current. Among these devices based on different Bi2Se3 morphologies, freestanding nanoplates shows the optimal mid-infrared characteristics, namely a photo-to-dark ratio of 2.0×104, a dark current of 0.21 pA, a response time of 23 ms, a specific detectivity of 6.1×1010 Jones (calculated) and 1.2×1010 Jones (measured) under 2.7 µm illumination and at room temperature. Notably, the specific detectivity of our devices are comparable to commercial InGaAs photodetectors. With the tunable- morphology growing technique and excellent photoresponding characteristics, Bi2Se3 nanomaterials are worth attention in optoelectronic field.

中文翻译：

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基于 Bi2Se3 迷宫和独立纳米板的高性能中红外光电探测

追求在中红外区域运行的光电器件是由基本利益和商业应用共同驱动的。层状 Bi2Se3 的窄带隙 (0.3 eV) 使其成为用于中红外光电探测的有前途的材料。然而，中红外光功率的弱吸收和高暗电流水平限制了其性能。本文采用供给控制技术调节Bi2Se3晶体的生长方式，获得了各种形貌的Bi2Se3晶体。当调整源质量时，纳米板图案从迷宫转变为独立式。由于垂直Bi2Se3纳米片的强红外吸收和光电转换效率，所制备的垂直Bi2Se3纳米片/Si异质结表现出优异的光响应和极低的暗电流。在这些基于不同 Bi2Se3 形态的器件中，独立式纳米板显示出最佳的中红外特性，即 2.0×104 的光暗比、0.21 pA 的暗电流、23 ms 的响应时间、2在 2.7 µm 照明和室温下，6.1×1010 Jones（计算）和 1.2×1010 Jones（测量）。值得注意的是，我们设备的特定探测能力可与商业 InGaAs 光电探测器相媲美。Bi2Se3纳米材料凭借其可调谐形态生长技术和优异的光响应特性，在光电领域备受关注。1×1010 Jones（计算）和 1.2×1010 Jones（测量）在 2.7 µm 照明和室温下。值得注意的是，我们设备的特定探测能力可与商业 InGaAs 光电探测器相媲美。Bi2Se3纳米材料凭借其可调谐形态生长技术和优异的光响应特性，在光电领域备受关注。1×1010 Jones（计算）和 1.2×1010 Jones（测量）在 2.7 µm 照明和室温下。值得注意的是，我们设备的特定探测能力可与商业 InGaAs 光电探测器相媲美。Bi2Se3纳米材料凭借其可调谐形态生长技术和优异的光响应特性，在光电领域备受关注。