Quasi-2D-Perovskite-Based Broadband Photodetector with a High I_on/I_off Ratio through Interface Engineering

A photodetector that can perceive light across a wide spectral range is crucial for various technological applications in imaging, sensing, and communication. However, the conventional silicon-based photodetector faces the challenge of absorption deficiency in the visible and ultraviolet regions, while the perovskite-based photodetector exhibits a weak response to near-infrared wavelengths. In this work, a broadband photodiode based on a silicon/quasi-two-dimensional perovskite structure was presented, which leverages the strengths of both materials to compensate for their respective deficiencies. Moreover, the introduction of the organic small-molecule material, phthalocyanine-based compound aluminum phthalocyanine chloride (AlClPc), as an interface modification layer effectively resolves the problem of high dark current in vertical devices, significantly reducing devices power consumption and enhancing the I on / I off ratio. The results show that the responsivity reaches up to 23.72 A/W, and the detectivity is 2.1 × 10 10 cm Hz 1/2 W 1– . Furthermore, the introduction of the interface layer increases the diode’s switching ratio from 27.55 to 2.35 × 10 2, achieving an order-of-magnitude improvement. Overall, this study demonstrates that the interface layer can effectively reduce dark current with a minimal impact on photocurrent attenuation. Furthermore, the integration of organic and inorganic structures, along with a modification layer, can be an optimal approach to promote the performance of the photodetectors, achieving a broadband, high-responsivity, and high I on / I off ratio.