The defect properties of semiconductors, especially those at grain boundaries (GBs) in polycrystalline semiconductor films, significantly influence their optoelectronic properties and consequently the performance of corresponding optoelectronic devices. However, despite extensive studies on GB defect properties in three-dimensional (3D) and two-dimensional (2D) semiconductors, research on GB defects in one-dimensional (1D) semiconductors remains unclear. Here, we report the intrinsic benign GB defect properties in 1D semiconductors, arising from their 1D crystal structure where no dangling bonds are present at GBs. Using the typical 1D optoelectronic material selenium (Se) as an example, we find that no defect states are introduced along the interchain direction of crystal planes through a combination of density of states and band structure calculations. We finally position the Kelvin probe force microscope probe on the cross-section of vertically oriented Se films to directly characterize the GB properties of polycrystalline Se films. We observe no significant changes in potential at the GBs, with the average plane potential difference being as low as approximately 10 mV, thus experimentally confirming the benign nature of GB defects in 1D materials. The combined theoretical and experimental results demonstrate the great potential of 1D semiconductors for optoelectronic applications.

Electrochemical carbon dioxide reduction reaction (CO₂RR), powered by advanced technologies such as solid oxide electrolysis cells (SOEC), is a promising method to convert CO₂ into valuable carbon-based products using renewable electricity. The high chemical stability of CO₂ requires catalysts to exhibit both high activity and stable electrocatalytic performance. However, catalysts that deliver high performance in CO₂RR are rare and still require further improvement. Here, we report a strategy that can efficiently enhance catalyst activity through Zn doping, which introduces active frustrated Lewis pairs (FLP) to improve the catalyst's ability to activate small molecules. A high current density of −1.85 A cm⁻² at 800 ℃ under a bias voltage of 1.5 V was achieved using the Sr₂Fe_0.8Zn_0.2MoO_6-δ (SFZn_0.2M) cathode with pure CO₂ feeding gas, surpassing previously reported results for perovskite oxide cathodes. This SOEC device also demonstrates excellent stability, with negligible degradation over tests lasting up to 110 h.