X-ray direct detectors are increasingly vital in medical diagnostics due to their high energy resolution and system integration. In recent years, metal-free halide perovskites (MFPs) have gained attention for their structural tunability and biocompatibility. However, existing devices often require high operating voltages to enhance carrier utilization efficiency, which can cause crystal damage and ion migration, limiting their applications.
The research team led by Prof. Jin Zhiwen at Lanzhou University’s School of Physics has designed a series of novel MFP materials by strategically regulating ion structures at different lattice sites. This approach optimizes internal crystal interactions, significantly improving device stability under high electric fields and intense radiation (as documented in Angew. Chem. Int. Ed. 2022, 2023; Adv. Mater. 2023; Nano Lett. 2023; npj Flexible Electron. 2024).
Recently, the team proposed a self-powered detection strategy leveraging the bulk photovoltaic effect (BPVE). By reducing cation symmetry at the A-site, they induced crystal polarity to enhance internal polarization fields, enabling efficient carrier separation and collection without external voltage. The resulting device achieved ultra-high sensitivity at 0V bias and pioneered an "in-sensor computing" imaging scheme for high-performance X-ray systems. These findings were published in Advanced Materials (2025, 37, 2502335).
Photoluminescence-Based Implied Open-Circuit Voltage Imaging for On-Site Perovskite Solar Cell Testing
A team from the University of New South Wales (UNSW) has developed a non-contact method to monitor perovskite solar cells (PSCs) outdoors using photoluminescence (PL) imaging and implied open-circuit voltage (iVOC) mapping. This approach enables real-time spatial analysis of performance degradation under natural sunlight—a first for quantitative outdoor iVOC imaging.
Traditional PL imaging requires dark environments to avoid ambient light interference. By contrast, this technique uses sunlight as the excitation source and a narrow bandpass filter (BPF) to isolate PL signals. The team validated it on 5 cm × 5 cm mini-modules and 0.06 cm² cells (>20% efficiency) in Sydney, achieving <5% iVOC error through single-BPF calibration. The low-cost setup includes an astronomical CMOS camera, industrial lenses, and off-the-shelf optical filters.
According to lead researcher Félix Gayot, this method provides spatial insights into degradation mechanisms (e.g., contact resistance changes, non-radiative recombination) that conventional outdoor monitoring (efficiency, fill factor) cannot capture. Future work will extend the technique to concentrator photovoltaics (CPV) and tandem solar cells.
Bill Gates-Backed Partnership Sets World Record for Perovskite Solar Efficiency
The U.S. National Renewable Energy Laboratory (NREL) and CubicPV, funded by Bill Gates, have achieved a record 24.0% certified efficiency for a perovskite photovoltaic micromodule. This milestone marks a critical step toward industrializing third-generation solar technology.
Perovskite materials offer advantages over silicon: lower manufacturing costs, lightweight flexibility, and a theoretical efficiency limit of 33%. The micromodule uses interconnected cells to balance high efficiency with large-area scalability—a challenge for perovskite commercialization. Innovations in thin-film deposition and interface design underpinned this breakthrough.
Globally, perovskite research is accelerating:
China: Hainan University (27.32% efficiency), Nanjing University (28.2% for all-perovskite tandem cells).
Applications: Building-integrated PV (BIPV), wearable electronics, and vehicle-integrated PV.
With optimized fabrication, perovskites could drive down system costs and expand renewable energy adoption.
