重庆师范大学物理与电子工程学院李万俊教授团队在光电化学型自供电日盲深紫外光电探测器研究中取得新进展。该团队基于低成本的磁控溅射技术和非晶氧化镓材料,在碳纤维纸上实现了高灵敏和超高稳定性的3D非晶氧化镓光电化学型自供电日盲深紫外探测器。该方法为高性能自供电日盲紫外探测器的研制提供了一种可行的参考。相关成果以“A simple, repeatable and highly stable self-powered solar-blind photoelectrochemical-type photodetector using amorphous Ga2O3 films grown on 3D carbon fiber paper”为题发表在《Journal of Materials Chemistry C》杂志上。课题组本科生黄利娟和胡郑蕊为论文共同第一作者,李万俊教授、叶利娟副教授、李泓霖副教授为共同通讯作者。
紫外线辐射是指波长范围为10至400 nm的电磁辐射,其占太阳总光谱的10%左右。根据国际照明委员会(ICE)推荐的定义,紫外线辐射通常分为以下子区域:紫外线A(UVA)光谱(315-400 nm),紫外线B(UVB)光谱(280至315 nm),紫外线C(UVC)光谱(200至280 nm)和极紫外(VUV)光谱(从10到~200 nm)。由于臭氧层的吸收,波长介于200-280 nm之间的UVC在地表可以忽略不计,称之为日盲紫外波段。工作在此波段的日盲探测器具有较低的背景噪声,使得其在导弹跟踪、火灾预警、高压电晕、紫外通信等诸多关键应用场景中发挥着重要作用。同时,在倡导“碳达峰、碳中和”的当今,低功耗器件受到了广泛关注,一种无需外接电压而实现器件自身运转的自供电技术已经成为研究热点。相对于传统的光电探测器,自供电探测器可以在无外加偏压的作用下实现光探测,具有独立、可持续性运作的特殊性质,能有效减少能量的损耗。
为此,该团队通过简易低成本的一步溅射法在碳纤维纸(CFP)上生长了三维(3D)非晶氧化镓薄膜(a-Ga2O3)。制备的a-Ga2O3/CFP核壳复合材料用作新型日盲光电化学(PEC)型光电探测器的光电阳极材料,通过构建固/液异质结所形成的内置电场可以有效地分离电子-空穴对。研制的a-Ga2O3/CFP光电化学型日盲紫外探测器件显示出良好的自供电能力,可应用于恶劣的户外环境。在无外部偏置电压的情况下,器件表现出较高的响应率(12.90 mA/W) 和较快的响应时间(0.15/0.13 s)。同时,器件具有超高的重复性,经过一年之后仍表现出优异自供电日盲探测能力。因此,基于3D非晶氧化镓光电化学型自供电日盲深紫外探测器有望在日盲深紫外检测领域展现出广阔的前景。
Fig. 1. (a-d) Scheme of the packaging procedure of a-Ga2O3/CFP photoelectrode; (e) Schematic diagram of typical PEC system built for evaluating the photoresponse behaviors of the a-Ga2O3/CFP photodetector.
Fig. 2. I-t responses of a-Ga2O3/CFP PEC photodetectors operating under 0 V bias with different sputtering time (thickness): (a) 0.5 h; (b) 1.0 h; (c) 1.5 h and (d) 2.0 h.
Fig. 3. (a-b) SEM morphologies of a-Ga2O3/CFP photoelectrode; (c-f) Local surface and the corresponding element mapping pictures of the a-Ga2O3/CFP photoelectrode; (g-i) EDX spectrum, the Ga and O element XPS spectra of the a-Ga2O3/CFP photoelectrode; (j-k) XRD patterns and Raman spectra of the a-Ga2O3/CFP photoelectrode; (l) The (αhv)^2~ hv plot of the a-Ga2O3 film deposited on c-Al2O3.
Fig. 4. (a) Response spectra of as-fabricated a-Ga2O3/CFP PEC PD at 0 V. (b) I-t responses of as-fabricated a-Ga2O3/CFP PEC PD at 0 V with different light intensity. (c) The response time of as-fabricated a-Ga2O3/CFP PEC PD at 0 V under 254 nm light intensity with 0.5 mW/cm2. (d) Comparison of photoresponse switching behaviors of as-fabricated and stored a-Ga2O3/CFP PEC PD at 0 V under 254 nm light intensity with 0.5 mW/cm2.
Fig. 5. Schematic illustration of self-powered a-Ga2O3/CFP PEC PDs under solar-blind DUV light irradiation.
论文信息:
Lijuan Huang#(本科生), Zhengrui Hu#(本科生), Hong Zhang, Yuanqiang Xiong, Shiqiang Fan, Chunyang Kong, Wanjun Li*, Lijuan Ye* and Honglin Li*. A simple, repeatable and highly stable self-powered solar-blind photoelectrochemical-type photodetector using amorphous Ga2O3 films grown on 3D carbon fiber paper. Journal of Materials Chemistry C, 2021, 9:10354.
论文连接:
https://doi.org/10.1039/D1TC02471J.