Self‐Assembled Bi ₂ O ₂ Se/ZnPc Hybrid Heterojunction Photodetector with Outstanding Responsivity

Abstract Bismuth oxyselenide (Bi ₂ O ₂ Se) is a 2D material characterized by high carrier mobility and remarkable stability, rendering it a highly promising candidate for photodetection applications. However, its practical utilization is limited by inherent challenges, including high dark current and slow photoresponse. To overcome these limitations, a Bi ₂ O ₂ Se/ZnPc heterojunction with type‐II band alignment is fabricated through a self‐assembly method. The 2D structure and strong light‐absorbing properties of zinc phthalocyanine (ZnPc) substantially improved the light absorption efficiency and photogain of Bi ₂ O ₂ Se. Consequently, the Bi ₂ O ₂ Se/ZnPc photodetector demonstrated a stable photoresponse across a broad spectral range spanning from 365 to 680 nm. Under 365 nm illumination, the device achieved a responsivity of 1.2 × 10 ³ A W ⁻¹ , a detectivity of 4.17 × 10 ¹¹ Jones, and rapid response and recovery times of 20 and 50 ms, respectively. Notably, Response up to 3.65 × 10 ³ A W ⁻¹ at applied gate voltage, the self‐assembled organic/inorganic van der Waals heterojunction effectively enhances photoresponse, responsivity, and tunability. This strategy holds substantial potential for advancing the optoelectronic performance of Bi ₂ O ₂ Se and other 2D materials, thereby enabling the development of next‐generation photodetector applications.