In Situ Encapsulation of Perovskite Quantum Dot Microwire Arrays with Small Organic Molecules for Enhanced Stability and Optoelectronic Performance

Abstract Perovskite quantum dots (PQDs) are ideal candidates for optoelectronic devices owing to their exceptional properties. However, their practical use is hindered by instability when exposed to moisture and oxygen. Encapsulation techniques have been effective in their enhancing stability, but improving device performance remains difficult. In this study, an in‐situ encapsulation technique using small organic molecules to encapsulate microwires assembled from PQDs is proposed. The encapsulation layer effectively shields the PQDs from environmental factors while maintaining excellent light‐absorption properties. The fabricated photodetectors exhibit a remarkably high responsivity of 430.6 A W ⁻¹ and an external quantum efficiency of 146 417%. For linearly polarized light, the devices demonstrate a dichroic ratio of up to 1.85. Even under ambient air conditions with 60% humidity for over a month, the device retains ≈60% of its original photocurrent.