Degradation In Ambient Conditions Research Articles

Outdoor Performance and Stability under Elevated Temperatures and Long‐Term Light Soaking of Triple‐Layer Mesoporous Perovskite Photovoltaics

AbstractLack of proven stability has become a major obstacle on the path of metal halide perovskite solar cells (PSCs), in particular methylammonium lead triiodide (MAPbI3), towards commercial viability. This correlates with the intrinsic affinity of MAPbI3 towards moisture and ambient air in particular, leading to its degradation in ambient conditions. We performed extensive stability tests to prove the durability of hole‐conductor‐free PSCs based on a triple‐layer architecture employing carbon as a back contact, including outdoor tests in the hot desert climate and indoor long‐term light soaking as well as heat exposure during 3 months at 80–85 °C. These results show no evidence for device degradation under the test conditions, confirming that the triple‐layer device architecture provides a promising path towards realizing efficient and stable perovskite photovoltaics.

Influence of P3HT:PCBM blend preparation on the active layer morphology and cell degradation

Polymeric solar cells have attracted much attention during the last years due to their lower fabrication cost and possibility of using flexible substrates. However, their efficiency is usually less than 5%. Among factors affecting polymeric solar cells efficiency, the active layer morphology related to blend preparation and annealing, is one of the most important. In this work we analyze the behavior of solar cells based on poly(3-hexylthiophene):[6,6]-phenyl-C 61-butyric acid methyl ester, P3HT:PCBM blends prepared under different conditions. Basic parameters are extracted from measured characteristics in dark and under illumination, while modeling is used to understand the mechanisms involved in the device behavior and during its degradation in ambient conditions, which are associated to the active layer characteristics.

Local structure and oxygen absorption in a-Si1−xCx(x< 0·4) alloys grown on silicon by plasma enhanced chemical vapour deposition

AbstractThe results of the structural analysis of amorphous hydrogenated silicon carbide layers obtained in a glow discharge from SiH4 and CH4 gas precursors are reported. The investigations are focused on the low range of C content with the aim of determining the local structure and chemical ordering for small x values. The main results indicate an increase in the mean number of H atoms per Si atom as the C concentration increases. In addition, as C is depositedfrom plasma methyl precursors (CH3), the high total H content of the films is responsible for a less densified structure, with the presence of voids. The influence of O absorption on the microstructure of the films after degradation in ambient conditions has also been studied. The concentration of O as afunction of depth and its preference for C or Si environments has been determined and discussed. Despite the presence of voids, H saturation of bonds is found to be responsible for the good resistance to oxidation.MST/3318