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A spin-coating-free fabrication sequence has been developed for the fabrication of highly efficient organic-inorganic halide perovskite solar cells (PSCs). A novel blow-drying method is demonstrated to be successful in depositing high quality mesoporous TiO2 (mp-TiO2), methylammonium lead halide (CH3NH3PbI3) perovskite and spiro-MeOTAD layers. When combined with compact TiO2 (c-TiO2) deposited by spray pyrolysis which is also a spin-coating-free process, a stabilized power conversion efficiency exceeding 17% can be achieved for the glass/FTO/c-TiO2/mp-TiO2/ CH3NH3PbI3/spiro-MeOTAD/Au device. This is the highest efficiency for PSCs fabricated without the use of spin-coating to our knowledge. This method provides a pathway towards a scalable process for fabricating high-performance, large area and reproducible PSCs.

AbstractConsolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since January 2017 are reviewed.

Abstract Herein, we report the dual functionality of a single n-type gallium nitride (n-GaN) layer as an electron transporter and transparent conductor, which has applications in reusable organic solar cells. After silicon doping with an optimized electron concentration, thin-film layer of GaN showed exceptional electrical properties including charge carrier mobility of 161 cm2 V−1s−1, electrical conductivity of 1.4ⅹ106 S cm−1, and sheet resistance of 11.1 Ω cm−2. Organic solar cells based on n-GaN exhibited power conversion efficiency comparable to those based on a conventional ITO/ZnO bilayered cathode. Furthermore, the n-GaN substrates exhibited reusability; due to excellent chemical stability of n-GaN, the reconstructed organic solar cells maintained their initial performance after the substrates were recycled. We suggest a new type of reusable n-GaN cathode layer featuring an integrated electron transporting layer and transparent electrode.

A simple and scalable interface-layer free monolithic perovskite/silicon tandem has been demonstrated achieving over 20% efficiency on a large area.

Abstract As stability of perovskite solar cells remains a significant research topic, it is important to be able to predict the long-term stability of any new kinds of perovskite solar cells when new perovskite absorber materials or transport layers or new cell structures are being demonstrated. This work reports a reliable method of determining degradation rate which is resulted from thermal stress. By incorporating three kinds of accelerated tests, the activation energy for photo-thermally driven degradation processes of perovskites solar cells was determined, which is then used to predict its long-term stability using an Arrhenius equation. In addition, thermal stability of CH3NH3PbI3, HC(NH2)2PbI3, PTAA (poly[bis(4-phenyl)(2,4,6-trimethyl phenyl)amine]) and Spiro-OMeTAD (2,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]−9,9'-spirobifluorene) are studied. The thermal stability of a planar HC(NH2)2PbI3/PTAA device is better than a planar HC(NH2)2PbI3/Spiro-OMeTAD device which in turn is better than a planar CH3NH3PbI3/Spiro-OMeTAD device due to better thermal stability of HC(NH2)2PbI3 and PTAA. It is predicted that a planar HC(NH2)2PbI3/PTAA device can have a lifetime of more than 3 years (or 1.5 years) at room temperature if 50% (or 25%) drop in power output can be tolerated. While these lifetimes are specific to perovskite material chosen, preparation method and solar cell design, the lifetime prediction method reported here can be verified experimentally. Therefore, the lifetime calculation method developed in this work is a quick and useful tool for determining the relative stability of a perovskite device especially when comparing the merits of different cell structure designs.

Abstract Past two years have seen the rapid emergence of a new class of solar cell based on mixed organic–inorganic halide perovskites. The optical and optical frequency dielectric properties of these perovskites at ambient temperatures are important both to the design of optimised solar cells and in other areas such as the refinement of electronic band structure calculations. Limited previous information has been published. The experimental optical and related dielectric constants of CH 3 NH 3 PbI 3− x Cl x and CH 3 NH 3 PbI 3 perovskite films are reported at 297 K as determined by detailed analysis of reflectance and transmittance data. Absorption coefficients are also extracted from these data and compared with a range of previously reported values.

Following the 1 release of the “Emerging PV reports” , the best achievements in the performance of emerging photovoltaic devices in diverse emerging photovoltaic research subjects are summarized, as reported in peer-reviewed articles in academic journals since August 2020. Updated graphs, tables and analyses are provided with several performance parameters, e.g. power conversion efficiency, open-circuit voltage, short-circuit current density, fill factor, light utilization efficiency, and stability test energy yield. These parameters are presented as a function of the photovoltaic bandgap energy and the average visible transmittance for each technology and application, and are put into perspective using, e.g., the detailed balance efficiency limit. The 2 instalment of the“Emerging PV reports” extends the scope towards tandem solar cells and presents the current state of the art in tandem solar cell performance for various material combinations.