As solar energy emerges as a pivotal renewable energy source, the environmental challenge of end-of-life photovoltaic (PV) module disposal intensifies.

Dislocation is a common extended defect in crystalline silicon solar cells, which affects the recombination characteristics of solar cells by forming deep‐level defect states in the silicon bandgap, thereby reducing the lifetime of minority carrier. Hence, reducing the impact of defects on device performance is an effective strategy to optimize the performance of photovoltaic devices. This article reviews the observation and engineering of dislocation in Si solar cell. The structure and deformation of Si can be directly observed by chemical etching combined with electron microscopy. Also, more information about dislocation is obtained indirectly by monitoring the electrical and optical properties of Si. The classification, density, distribution of dislocations, and their interactions with other defects in Si can affect the lifetime of minority carriers and thereby reduce the performance of Si solar cells. In order to achieve higher cell efficiency, crystals with less or even no dislocation should be obtained. In addition to the specification of controlling the relevant parameters during the growth of silicon ingots to obtain the minimum dislocation density, it is necessary to study the behavior of dislocation in Si wafers under the combined action of external stress, temperature, and other defects.

Carrier collection and light absorption is a couple of contradiction for polymer solar cells (PSCs) because of the limited carrier mobility and optical absorption coefficient for the organic active layers. In this article, the concept of “bridging for carriers” is introduced by embedding metal oxide (ZnO for electrons and NiO $_{x}$ for holes in this study) nanoparticles into the photoactive layer of PSCs to improve exciton separation, enhance carrier transport, reduce electron–hole recombination and thus facilitate carrier collection. It is found that ∼57.6% increase in the power conversion efficiency, i.e., from 1.98% to 3.12% for the optimal addition of ZnO and NiO $_{x}$ into the active layer of the P3HT:PC $_{61}$ BM blend is achieved as compared with the control case without adding ZnO and NiO $_{x}$ nanoparticles. In combination with the simple hydrothermal method of preparing these metal oxide nanoparticles, this study is believed to provide valuable contribution to explore facile approaches to address the contradiction of carrier collection and light absorption for PSCs by bridging for carriers in the photoactive layer.