A perovskite single crystal with one-dimensional structure enables photodetection with negligible hysteresis

Abstract

The robust material tunability of the hybrid organic–inorganic perovskite (HOIP) has attracted considerable research interests to explore the application in photoelectronic devices. Huge hysteresis has been recognised as a main problem in HOIP-based photoelectric devices; the origin of hysteresis has been attributed to the ion migration and trap states in HOIP materials. In this study, we designed and synthesised a HOIP single crystal with one-dimensional structure where the PbI₄²⁻ octahedron is caged by the organic chains. The ion migration can be dramatically suppressed by the quantum size effect. Besides, in the single crystal trap states density is ultra-low due to the absence of grain boundaries. As a result, photodetectors based on this 1D HOIP single crystal show negligible hysteresis I–V curves. Moreover, a high quality ohmic contact is formed between electrodes and 1D HOIP, which is beneficial for photocarrier extraction. A responsivity of 80 mA W⁻¹ and EQE of 30% are realised. The response speed is determined to be less than 0.4 ms. In addition, the photodetectors based on the novel 1D single crystal present good stability; after 3 months of ambient storage, 85% of its original photocurrent generation ability is retained.