Lithium‐Doped CuO Nanosheets: Structural Transformation, Optical, and Electrical Characteristics with Enhanced Photocatalytic and Solar Cell Performance

Energy and environmental stuff are two of the main worries for humanity, and nanoscience plays a key role in providing the solution. Huge nano‐research activities have attracted lot of attention in the current scenario. However, designing the material with enhanced optoelectronic properties remains the foremost challenge. In the present work, the Li doped CuO nanosheets are synthesized by the chemical route and examined in photovoltaics and environmental remediation applications. The crystallographic and optical study reveals that crystallite size and bandgap decrease with an increase in lithium‐doping concentration up to 5 mole % and beyond that a reverse trend is observed. Additionally, impedance study has shown the significant contribution of lithium‐ions to the total capacitance and resistivity. Further, the photoactivity of Cu1−xLixO nanosheets (optimum concentration of Cu1−xLixO NSs (x = 0.05)) is projected to the degradation of methylene blue (MB) and used to fabricate bulk heterojunction solar cell together with P3HT and PCBM blend, respectively. The ITO/PEDOT:PSS/P3HT:PC70BM:Cu1−xLixO (x = 0.05)/LiF/Al solar cell realized higher power‐conversion efficiency η ˜ 3.91 than their corresponding pristine device η ˜ 2.98 with enhanced photocurrent density from 9.026 to 11.56 mA cm−2. The proliferation in photocatalysts and solar cells efficiency of Cu1−xLixO (x = 0.05) is mainly attributed to the higher light absorption and lesser electron‐hole recombination. The approach for the synthesis of Cu1−xLixO NSs as potential donor material and device prototypes fabricated is completely safe and cost‐effective.