A two-step sequential blade-coating process in air to fabricate high-efficiency perovskite solar cells and modules.

Perovskite solar cells represent a promising photovoltaic technology, which achieves record power conversion efficiencies over 24%. However, a problem on the commercial processing is the unavoidable efficiency loss during the scalable fabrication of perovskite solar module. The efficient and reliable fabrications of high‐quality large‐area perovskite films guarantee commercialized up‐scaling of perovskite solar cells with high efficiency. Herein, a simple dynamic antisolvent quenching (DAS) process is presented to understand large‐area uniform perovskite films to obtain an efficient perovskite solar module. This method provides a facile and universal approach to fabricate cracks‐free and uniform large‐area mixed‐cation perovskite films. A champion module device (10 × 10 cm2) with efficiency of 17.82% (another module with certified efficiency of 17.4%) is obtained using DAS process.

Hybrid perovskite solar cells (PSC) have gained stupendous achievement in single/tandem solar cell, semitransparent solar cell and flexible devices. Aiming for potential commercialization of perovskite photovoltaic technology, up scalable processing is crucial for all function layers in PSC. Herein we present a study on room temperature magnetron sputtering of tin oxide electron transporting layer (ETL) and apply it in a large area PSC for low cost and continues manufacturing. The SnO2 sputtering targets with varied oxygen and deposition models are used. Specifically, the working gas ratio of Ar/O2 during the radio frequency sputtering process plays a crucial role to obtain optimized SnO2 film. The sputtered SnO2 films demonstrate similar morphological and crystalline properties, but significant varied defect states and carrier transportation roles in the PSC devices. With further modification of thickness of SnO2, the PSCs based on sputtered SnO2 ETL shows a champion efficiency of 18.20% in small area and an efficiency of 14.71% in sub-module with an aperture area of 16.07 cm 2 , which is the highest efficiency of perovskite sub module with sputtered ETLs.

No abstract

Formamidinium (FA)-based perovskite solar cells (PSC) show enhanced stability compared to their methylammonium (MA)-based counterparts. However, their stability needs to be further enhanced for the potential commercial applications. We demonstrate here that the high-quality thin film can be obtained for the FA-based perovskite with remarkably enhanced moisture stability using a confined-pressure annealing (CPA) processing and controlling the amount of Cs introduced into the FAPbI 3 perovskite precursor solution. Without additional 2D cation additives, surface passivation, or encapsulation, no phase degradation was observed for the Cs 0.1 FA 0.9 PbI 3 perovskite under a humidity of 70% RH for over 500 h. The unencapsulated device maintained over 70% performance for 500 h compared to <80 h of the conventional processed devices, which is comparable to the outstanding moisture stability of the 2D/3D perovskites. The FAbased perovskite grain size was promoted to over 1 μm with a high static water contact angle up to 112°. The surface cation composition was varied with the concentrated FA cation species at the surface while homogenized Cs/FA distribution inside the film. The trapped-state density and carrier recombination rate were also reduced with a high fill factor of 82% and an efficiency over 20.23%. This work suggests that the intrinsic stability of the 3D perovskite could be further enhanced by adjusting the surface compositions during the crystallization process.

The inclusion of potassium in perovskite solar cells (PSCs) has been widely demonstrated to enhance the power conversion efficiency and eliminate the hysteresis effect. However, the effects of the locations K + cations on the charge-carrier dynamics remain unknown with respect to achieving a more delicate passivation design for perovskite interfaces and bulk films. Herein, we employ the combined electrical and ultrafast dynamics analysis for the perovskite film to distinguish the effects of bulk doping and interfacial passivation of the potassium cation. Transient absorption spectroscopy indicates an enhancement of chargecarrier diffusion for K + -doped PSCs (from 808 to 605 ps), and charge-carrier transfer is significantly promoted by K + interface passivation (from 12.34 to 1.23 ps) compared with that of the pristine sample. Importantly, K + doping can suppress the formation of wide bandgap perovskite phases (e.g., FAPbI 0.6 Br 2.4 and FAPbI 1.05 Br 1.95 ) that generate an energy barrier on the charge-carrier transport channel.

No abstract

To cope with huge carbon emission pressure, China has implemented a carbon emissions trading pilot policy that aims to provide reasonable suggestions for the smooth operation of the national carbon market. This paper selects the provincial panel data in China from 2005 to 2019 and uses the propensity score matching-difference in difference (PSM-DID) method to evaluate the carbon emission policy’s reduction effect. Based on carbon emissions (CE) and carbon emission intensity (CI), provinces and cities are divided into four regions, and each region is verified by spatial difference analysis. Furthermore, the mediating effects of carbon emission reduction through the dual aspects of technological progress and industry structure are also discussed. Results verified that, (1) under the carbon emission trading policy, regional carbon emissions and carbon emission intensity are both significantly reduced. (2) Technological progress helps to reduce carbon emissions, while industrial structure shows no obvious contribution. (3) The four regions all show ideal emission reduction effects, of which the High CE-High CI region shows the best, but is greatly restricted by techniques. The industrial structure of the High CE-Low CI region needs to be further optimized for carbon reduction. In the Low CE-High CI region, the carbon emissions brought by economic development fail to effectively improve per capita GDP. The Low CE-Low CI region contributes greatly to carbon emission reduction with technical advantages.