Efficient heterojunction charge transfer for ultraviolet to short-wave infrared broadband photodetectors

Broadband photodetectors (PDs) spanning the ultraviolet to short-wavelength infrared (UV-SWIR) spectrum are highly desirable for diverse applications including environmental monitoring, biomedical imaging, and industrial inspection. However, achieving high responsivity and fast response across such a wide spectral range remains a significant challenge, often limited by the narrow bandgap absorption of single materials or inefficient carrier collection in conventional device architectures. To address this problem, we designed and fabricated a novel heterojunction photodetector based on CsPbI 3 perovskite quantum dots (PQDs) and In 0.53 Ga 0.47 As layer . The core innovation lies in the engineered band alignment at the heterojunction interface, which facilitates exceptionally efficient charge transfer and separation. Compared to the bare CsPbI 3 PQDs (UV–visible) or In 0.53 Ga 0.47 As PDs (SWIR), this CsPbI 3 /In 0.53 Ga 0.47 As heterojunction PDs not only obtained the detection wavelength from UV to SWIR, but also improve the photocurrent across the entire range. Furthermore, the CsPbI 3 PQDs/In 0.53 Ga 0.47 As heterojunction PDs demonstrate outstanding detectivity of above 10 10 Jones. Meanwhile, the PDs also demonstrate significantly long-term stability, and the photocurrent of the device maintains 96.5 % of the initial one after 10000 cycles. This work demonstrates the pivotal role of efficient interfacial charge transfer in heterojunctions and provides a promising strategy for developing next-generation optoelectronic devices covering the UV-SWIR window.