Monolithic Micro Light-Emitting Diode/Metal Oxide Nanowire Gas Sensor with Microwatt-Level Power Consumption
Monolithic Micro Light-Emitting Diode/Metal Oxide Nanowire Gas Sensor with Microwatt-Level Power Consumption
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DOI：
10.1021/acssensors.9b02487
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发表时间：
2020-02-01
期刊：
影响因子：
8.9
通讯作者：
Park, Inkyu
中科院分区：
文献类型：
--
作者：
Cho, Incheol;Sim, Young Chul;Park, Inkyu
介绍了一种将气敏半导体金属氧化物纳米线集成在微型发光二极管（mu LED）上的高性能单片光敏气体传感器。μ LED显示出改善的辐照度和能量转换效率（即，外部量子效率（EQE），因为LED的尺寸从200 × 200 μ m（2）（辐照度为46.5 W/cm（2），EQE为4%）减小到30 × 30 μ m（2）（辐照度为822.4 W/cm（2），EQE为9%）。气敏氧化锌（ZnO）纳米线的顶部直接合成的μ LED通过水热反应。传感元件和mu LED传感器平台之间的直接接触导致高光耦合效率，最大限度地降低了传感器的功耗。此外，感测性能（即，随着LED尺寸的减小，在最佳操作功率下的灵敏度）得到改善。制造的最小的气体传感器（有效面积= 30 × 30 μ m（2））在最佳工作功率（类似于184 pW）下显示出优异的NO2灵敏度（Δ R/R = 605%至1 ppm NO2）。此外，该传感器显示出较低的检测限（类似于14.9 ppb）和对高湿度条件的鲁棒性，这证明了其在移动的物联网（IoT）设备中的实际应用潜力。
High-performance, monolithic photoactivated gas sensors based on the integration of gas-sensitive semiconductor metal oxide nanowires on micro light-emitting diodes (mu LEDs) are introduced. The mu LEDs showed improved irradiance and energy conversion efficiency (i.e., external quantum efficiency, EQE), as the size of LEDs was reduced from 200 x 200 mu m(2) (irradiance of 46.5 W/cm(2) and EQE of 4%) to 30 x 30 mu m(2) (irradiance of 822.4 W/cm(2) and EQE of 9%). Gas-sensitive zinc oxide (ZnO) nanowires were directly synthesized on top of the mu LED through a hydrothermal reaction. The direct contact between the sensing component and mu LED sensor platform leads to high light coupling efficiency, minimizing power consumption of the sensor. Furthermore, the sensing performance (i.e., sensitivity) at optimal operating power was improved as the LED size was reduced. The smallest fabricated gas sensor (active area = 30 x 30 mu m(2)) showed excellent NO2 sensitivity (Delta R/R, = 605% to 1 ppm NO2) at the optimal operating power (similar to 184 pW). In addition, the sensor showed a low limit of detection (similar to 14.9 ppb) and robustness to high humidity conditions, which demonstrate its potential for practical applications in mobile internet of things (IoT) devices.