Preferential Crystallographic Orientation via α-CN Stereo-directional Effect for Superior Perovskite Indoor Photodetectors

Abstract

This study introduces a novel approach to enhance perovskite crystallization for efficient indoor energy harvesting through the addition of a-chloronaphthalene (a-CN) as an anti-solvent additive. We demonstrate that a-CN induces a "Stereo-directional Effect" during crystallization, where its bulky naphthalene structure facilitates preferential crystal growth along specific crystallographic planes. X-ray diffraction analysis reveals that a-CN treatment significantly enhances crystallinity, with the (110) plane showing a 245.47% increase in crystallite size compared to 150.45% for the control sample. Morphological characterization confirms larger grain formation and more uniform film topography in a-CN treated samples. These structural improvements translate to superior electronic properties, including reduced defect state energy (56.5 meV vs. 71.7 meV) and improved ideality factor (1.97 vs. 2.16). Under indoor lighting conditions, a-CN treated devices demonstrate remarkable performance enhancement, achieving a power conversion efficiency of 32.23% at 1200 lux compared to 28.04% for the control device. The detectivity at 720 nm reaches 9.17 x 1012 Jones, representing a 65.8% improvement over the control. This work establishes a direct correlation between the Stereo-directional Effect of a-CN and enhanced device performance, particularly under indoor low-light conditions, providing a simple yet effective strategy for developing high-efficiency indoor energy harvesting systems based on perovskite materials