In this study, we provide fundamental understanding on defect properties of the Sb₂(S,Se)₃ absorber film and the impact on transmission of photo-excited carriers in N–i–P architecture solar cells by both deep level transient spectroscopy (DLTS) and optical deep level transient spectroscopy (ODLTS) characterizations. Through conductance–voltage and temperature-dependent current–voltage characterization under a dark condition, we find that the Sb₂(S,Se)₃ solar cell demonstrates good rectification and high temperature tolerance. The DLTS results indicates that there are two types of deep level hole traps H1 and H2 with active energy of 0.52 eV and 0.76 eV in the Sb₂(S,Se)₃ film, and this defect property is further verified by ODLTS. The two traps hinder the transmission of minority carrier (hole) and pinning the Fermi level, which plays a negative role in the improvement of open-circuit voltage for Sb₂(S,Se)₃ solar cells. This research suggests a critical direction toward the efficiency improvement of Sb₂(S,Se)₃ solar cells.

The compressive sensing framework aims to stably recover sparse signals at reduced sampling rate. Recent research has shown that only the sign information of the measurements can achieve accurate signal recovery. Most work focused on the real-valued signals. In many applications, however, the signals are complex-valued. Also, the existing reconstruction algorithms always involve large matrix-vector multiplications which make them more time and memory consuming than traditional matched filtering-based methods. In this paper, we propose a 1-bit compressive sensing reconstruction algorithm for recovering complex sparse signals using approximated observation matrix which is deduced from the inverse of chirp-scaling method. This algorithm directly operates on complex data and greatly reduce the computation time and memory usage. Both simulated and real data validate the efficiency of the proposed algorithm.