Alleviating the Angular Dependence of Perovskite Solar Cells via Light‐Harvesting Nanostructure

Over the past decade, perovskite solar cells (PSCs) have witnessed a remarkable surge in power conversion efficiency ( PCE ). However, the electrical output performance of PSCs is dependent on the incident angle of solar radiation, and energy loss occurs during photovoltaic conversion when light impinges at angles. Herein, a perovskite‐light‐absorbed layer with inverse opal structure is used to fabricate PSCs and reduce the angular dependence of the performance. In the results, it is demonstrated that ordered periodic perovskite inverse opal (PVSK–IO) not only exhibits a remarkable slow‐photon effect for enhancing the absorption of sunlight near the photonic bandgap (PBG), but also promotes the carrier transfer by expanding the contact area with hole‐transport layer. Moreover, the slow‐photon region of PBG can be intentionally tuned by changing the direction of sunlight illumination, thereby more intuitively delaying and storing light in the PVSK–IO layer. As a consequence, the slow‐photon effect originated from the PVSK–IO structure efficiently improves the short‐circuit current density, resulting in a higher PCE than that of planar devices under the irradiation from different incident angles. In this research, a rational strategy is offered for enhancing the performance of PSCs while alleviating their angular dependence.