Flexible SnSe Photodetectors with Ultrabroad Spectral Response up to 10.6 μm Enabled by Photobolometric Effect
Flexible SnSe Photodetectors with Ultrabroad Spectral Response up to 10.6 μm Enabled by Photobolometric Effect
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DOI：
10.1021/acsami.0c09561
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发表时间：
2020-08-05
影响因子：
9.5
通讯作者：
Yan, Keyou
中科院分区：
文献类型：
--
作者：
Xu, Hanyang;Hao, Lanzhong;Yan, Keyou
现代光电子学对辐射探测的要求是宽光谱响应，但这仍然是一个巨大的挑战。在这里，我们报道了一种基于高质量的SnSe薄膜的新型超宽带光电探测器，它甚至能够探测能量远远低于其光学带隙的光子。采用溅射法在氯化钠衬底上通过45度的面内旋转外延生长了晶片尺寸的SnSe超薄膜。该光电探测器在光导模式下对紫外-可见光-近红外(UV-VIS-NIR)光进行灵敏检测，并在室温下对长波长红外显示异常响应。在10.6微米的中红外光下，所制得的光电探测器具有较大的光响应率0.16A·W~(-1)和较快的响应率，与其他结果相比提高了3个数量级。亚带隙响应是由光热效应引起的热致载流子引起的。薄膜的电阻温度系数为-2.3%~4.4%K-1，与商用测辐射热探测器相当，证实了这一机理。此外，转移到聚合物模板上的柔性器件还显示出高机械耐久性和200次弯曲循环的稳定性，这表明在开发可穿戴光电器件方面具有巨大的潜力。
A broad spectral response is highly desirable for radiation detection in modern optoelectronics; however, it still remains a great challenge. Herein, we report a novel ultrabroadband photodetector based on a high-quality tin monoselenide (SnSe) thin film, which is even capable of detecting photons with energies far below its optical band gap. The wafer-size SnSe ultrathin films are epitaxially grown on sodium chloride via the 45 degrees inplane rotation by employing a sputtering method. The photodetector delivers sensitive detection to ultraviolet-visible-near infrared (UV-Vis-NIR) lights in the photoconductive mode and shows an anomalous response to long-wavelength infrared at room temperature. Under the mid-infrared light of 10.6 mu m, the fabricated photodetector exhibits a large photoresponsivity of 0.16 A W-1 with a fast response rate, which is similar to 3 orders of magnitude higher than other results. The thermally induced carriers from the photobolometric effect are responsible for the sub-bandgap response. This mechanism is confirmed by a temperature coefficient of resistance of -2.3 to 4.4% K-1 in the film, which is comparable to that of the commercial bolometric detectors. Additionally, the flexible device transferred onto polymer templates further displays high mechanical durability and stability over 200 bending cycles, indicating great potential toward developing wearable optoelectronic devices.