Cubic silicon carbide (3C‐SiC) has superior mobility and thermal conduction over that of widely applied hexagonal 4H‐SiC. Moreover, much lower concentration of interfacial traps between insulating oxide gate and 3C‐SiC helps fabricate reliable and long‐life devices like metal‐oxide‐semiconductor field effect transistors. However, the growth of high‐quality and wafer‐scale 3C‐SiC crystals has remained a big challenge up to now despite decades‐long efforts by researchers because of its easy transformation into other polytypes during growth, limiting the development of 3C‐SiC‐based devices. Herein, we report that 3C‐SiC can be made thermodynamically favored from nucleation to growth on a 4H‐SiC substrate by top‐seeded solution growth technique, beyond what is expected by classical nucleation theory. This enables the steady growth of high‐quality and large‐size 3C‐SiC crystals (2–4‐inch in diameter and 4.0–10.0 mm in thickness) sustainable. The as‐grown 3C‐SiC crystals are free of other polytypes and have high‐crystalline quality. Our findings broaden the mechanism of hetero‐seed crystal growth and provide a feasible route to mass production of 3C‐SiC crystals, offering new opportunities to develop power electronic devices potentially with better performances than those based on 4H‐SiC.

Al addition modifies the interfacial energy of SiC/solution during the growth of SiC single crystals via TSSG, and is beneficial to smoothing the growth surface, improving the crystalline quality, stabilizing the 4H polytype, and increasing the growth rate.

Substantial ultraviolet (UV) photodetector research has been pursued in recent decades. In this paper, we report the self-powered UV vertical photovoltaic effect (VPE) and lateral photovoltaic effect (LPE) with high sensitivity and fast-relaxation time in NdNiO₃/Nb:SrTiO₃ (NNO/NSTO) heterojunctions. The rectifying behavior indicates that the large built-in electric field is formed in the p-n junctions. The open circuit voltage of VPE is as high as 0.4 V under 266 nm laser illumination, with the relaxation time of 1.8 μs. The highest position sensitivity of the LPE is about 32 mV/mm, and its optical relaxation time is about 7.4 μs. The two distinct resistance states observed for the NNO film deposited on NSTO and SrTiO₃ (STO) substrates suggest that the transport of photo-excited carriers in VPE and LPE is mainly through the NSTO single crystal, resulting in a fast relaxation time of the photovoltaic effect in NNO/NSTO p-n junctions. The fast relaxation and high sensitivity of the VPE and LPE make the NNO/NSTO junction a promising candidate for a wide range of self-powered ultraviolet/near-ultraviolet optoelectronic applications.