Broadening the Spectral Response of Perovskite Photodetector to the Solar-Blind Ultraviolet Region through Phosphor Encapsulation

• Published in: ACS applied materials & interfaces Vol. 13; no. 37; pp. 44509 - 44519
• Main Authors: Zhang, Xuning, Liu, Xingyue, Sun, Bo, Ye, Haibo, He, Chunhua, Kong, Lingxian, Shi, Tielin, Liao, Guanglan, Liu, Zhiyong
• Format: Journal Article
• Language: English
• Published: American Chemical Society 22.09.2021
• Subjects: Functional Inorganic Materials and Devices; phosphor encapsulation; perovskite; UV detection; photodetector; flame detection
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c09719

Hybrid perovskite photodetectors generally exhibit brilliant performance for photodetecting in the visible spectrum but poor detectability in the solar-blind ultraviolet (UV) region. To break through the bottleneck, we demonstrate a novel strategy to broaden the spectral response of perovskite photodetectors to the solar-blind UV region through phosphor encapsulation. The high photoluminescence quantum yield trichromatic phosphor capping layer achieves an extended spectral response to the solar-blind UV region through effectively down-converting the incident UV light into visible light. In addition, an external quantum efficiency of up to 12.13%@265 nm is achieved without bias voltage, while the initial value is near zero. The corresponding spectral responsivity and detectivity are 0.0269 A/W and 7.52 × 1011 Jones, respectively. Thus, the photodetectors show a high photocurrent and on/off ratio, increasing by roughly 2 orders of magnitude. Moreover, the photodetectors exhibit a large linear dynamic range of 105 dB, fast response times of 50.16/51.99 μs, and excellent stability. The practical applications for flame detection and UV-based communication are further explored. This work provides a new way to achieve UV light detection based on perovskite photodetectors. Perhaps, it may also be a promising alternative for wide-band gap semiconductors to realize the urgent pursuit of UV detection.