Flexible Self-Powered GaN Ultraviolet Photoswitch with Piezo-Phototronic Effect Enhanced On/Off Ratio

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• 作者：Mingzeng Peng ; Yudong Liu ; Aifang Yu ; Yang Zhang ; Caihong Liu ; Jingyu Liu ; Wei Wu ; Ke Zhang ; Xieqing Shi ; Jinzong Kou ; Junyi Zhai ; Zhong Lin Wang
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：January 26, 2016
• 年：2016
• 卷：10
• 期：1
• 页码：1572-1579
• 全文大小：526K
• ISSN：1936-086X

文摘

Flexible self-powered sensing is urgently needed for wearable, portable, sustainable, maintenance-free and long-term applications. Here, we developed a flexible and self-powered GaN membrane-based ultraviolet (UV) photoswitch with high on/off ratio and excellent sensitivity. Even without any power supply, the driving force of UV photogenerated carriers can be well boosted by the combination of both built-in electric field and piezoelectric polarization field. The asymmetric metal–semiconductor–metal structure has been elaborately utilized to enhance the carrier separation and transport for highly sensitive UV photoresponse. Its UV on/off ratio and detection sensitivity reach to 4.67 × 10⁵ and 1.78 × 10¹² cm·Hz^0.5 W^1–, respectively. Due to its excellent mechanical flexibility, the piezoelectric polarization field in GaN membrane can be easily tuned/controlled based on piezo-phototronic effect. Under 1% strain, a stronger and broader depletion region can be obtained to further enhance UV on/off ratio up to 154%. As a result, our research can not only provide a deep understanding of local electric field effects on self-powered optoelectronic detection, but also promote the development of self-powered flexible optoelectronic devices and integrated systems.