On-Chip Full-UV-Band Photodetectors Enabled by Hot Hole Extraction
Achieving on-chip, full-UV-band photodetection across UV-A (315-400 nm), UV-B (280-315 nm), and UV-C (100-280 nm) bands remains challenging due to the limitations in traditional materials, which often have narrow detection ranges and require high operating voltages. In this study, we introduce a self-driven, on-chip photodetector based on a heterostructure of hybrid gold nanoislands (Au NIs) embedded in H-glass and cesium bismuth iodide (Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>). The Au NIs act as catalytic nucleation sites, enhancing crystallinity and facilitating the vertical alignment of the interconnected Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> petal-like thin film. A built-in electric field developed at the heterojunction efficiently separates hot holes generated in the Au NIs under UV illumination, transferring them to the valence band of Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> and minimizing recombination losses. The device demonstrates an ultrahigh open-circuit voltage of 0.6 V, exceptional responsivity of 0.88 A/W, and a detection threshold of 90 nW/cm<sup>2</sup>, outperforming the existing thin film-based UV photodetectors under self-driven mode. Long-term stability tests confirmed robust operational reliability under ambient conditions for up to eight months. This architecture, driven by efficient hot hole dynamics, represents a significant advancement for full-UV-band optoelectronics with promising applications in environmental monitoring, flame detection, biomedical diagnostics, and secure communication systems.
Authors
- K. D. M. Rao
- Indrajeet Mandal (ORCID: https://orcid.org/0000-0002-8808-4602)
- Sayan Kanungo (ORCID: https://orcid.org/0000-0001-7500-6982)
- Sougata Karmakar (ORCID: https://orcid.org/0000-0001-9649-0865)
- Nitya Nand Gosvami (ORCID: https://orcid.org/0000-0003-4082-9887)
- Manohar Chirumamilla (ORCID: https://orcid.org/0000-0002-6812-286X)
- Gurupada Ghorai (ORCID: https://orcid.org/0000-0001-9410-6022)
- S. Maidul Haque (ORCID: https://orcid.org/0000-0001-7569-6370)
- A. V. Muhammed Ali
- Tamilarasan Palanisamy (ORCID: https://orcid.org/0000-0001-9957-8440)
- N. M. Anoop Krishnan (ORCID: https://orcid.org/0000-0003-1500-4947)
- M. Sridevi (ORCID: https://orcid.org/0000-0002-0226-6430)
- Amarnath Reddy Allu (ORCID: https://orcid.org/0000-0003-0450-0929)
- N. K. Murugasenapathi
- Rajiv K. Singh (ORCID: https://orcid.org/0000-0003-2602-9293)
- S.G. Ash
Institutions
- Central Electrochemical Research Institute (IN)
- Central Glass and Ceramic Research Institute (IN)
- National Physical Laboratory (GB)
- Universität Hamburg (DE)
- Indian Association for the Cultivation of Science (IN)
- Birla Institute of Technology and Science - Hyderabad Campus (IN)
- Advanced Device Technology (United States) (US)
- Indian Institute of Technology Delhi (IN)
- Birla Institute of Technology and Science, Pilani (IN)
- Hamburg University of Technology (DE)
- CSIR National Physical Laboratory of India (IN)
- Aalborg University (DK)
- Academy of Scientific and Innovative Research (IN)
Publication Details
- Journal
- ACS Nano
- Published
- 2025-02-06
- DOI
- https://doi.org/10.1021/acsnano.4c16106
- Citations
- 6
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 4.38
Funders
- Science and Engineering Research Board
- UGC-DAE Consortium for Scientific Research, University Grants Commission