In recent years, the power conversion efficiency of perovskite solar cells has increased to reach over 20%. Finding an effective means of defect passivation is thought to be a promising route for bringing further increases in the power conversion efficiency and the open-circuit voltage (VOC) of perovskite solar cells. Here, we report the use of an organic halide salt phenethylammonium iodide (PEAI) on HC(NH2)2–CH3NH3 mixed perovskite films for surface defect passivation. We find that PEAI can form on the perovskite surface and results in higher-efficiency cells by reducing the defects and suppressing non-radiative recombination. As a result, planar perovskite solar cells with a certificated efficiency of 23.32% (quasi-steady state) are obtained. In addition, a VOC as high as 1.18 V is achieved at the absorption threshold of 1.53 eV, which is 94.4% of the Shockley–Queisser limit VOC (1.25 V). Planar perovskite solar cells that have been passivated using the organic halide salt phenethylammonium iodide are shown to have suppressed non-radiative recombination and operate with a certified power conversion efficiency of 23.3%.

Surface passivation of perovskite film for efficient solar cells

Although organic photovoltaic (OPV) cells have many advantages, their performance still lags far behind that of other photovoltaic platforms. A fundamental reason for their low performance is the low charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption. In this work, guided by a semi-empirical model analysis and using the tandem cell strategy to overcome such issues, and taking advantage of the high diversity and easily tunable band structure of organic materials, a record and certified 17.29% power conversion efficiency for a two-terminal monolithic solution-processed tandem OPV is achieved.

https://science.sciencemag.org/content/sci/early/2018/08/08/science.aat2612.full.pdf

Organic and solution-processed tandem solar cells with 17.3% efficiency

The efficiency of silicon solar cells has a large influence on the cost of most photovoltaics panels. Here, researchers from Kaneka present a silicon heterojunction with interdigitated back contacts reaching an efficiency of 26.3% and provide a detailed loss analysis to guide further developments.

Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26

The efficiencies of perovskite solar cells have gone from single digits to a certified 22.1% in a few years' time. At this stage of their development, the key issues concern how to achieve further improvements in efficiency and long-term stability. We review recent developments in the quest to improve the current state of the art. Because photocurrents are near the theoretical maximum, our focus is on efforts to increase open-circuit voltage by means of improving charge-selective contacts and charge carrier lifetimes in perovskites via processes such as ion tailoring. The challenges associated with long-term perovskite solar cell device stability include the role of testing protocols, ionic movement affecting performance metrics over extended periods of time, and determination of the best ways to counteract degradation mechanisms.

http://science.sciencemag.org/content/sci/358/6364/739.full.pdf

Promises and challenges of perovskite solar cells

ZnS nanostructures: From synthesis to applications

Provided is a solar cell manufacturing method which can simplify the manufacturing process and suppress lift-off layer delamination The solar cell manufacturing method includes: a step for forming a first semiconductor layer material film on the rear surface of a semiconductor substrate 11; a step for forming a lift-off layer on the material film; a step for forming a protective layer on the lift-off layer; a step for forming a first semiconductor layer 25, a lift-off layer 41, and a protective layer 51, which are patterned, in a first region 7 by using a pattern printing resist 90, and for removing the pattern printing resist 90 and the protective layer 51; a step for forming a second semiconductor layer material film on the lift-off layer 41 in the first region 7 and in a second region 8; and a step for forming a patterned second semiconductor layer in the second region 8 by removing the lift-off layer 41, wherein the protective layer 51, during the step for forming the first semiconductor layer, protects the lift-off layer 41 from a solution that is used for the patterning and is removed by a solution that removes the pattern printing resist 90

Solar cell manufacturing method

Provided is a method for producing solar cells which makes it possible to reduce the cost of the solar cells and suppress a decline in the performance thereof A method for producing back electrode-type solar cells which includes a step for forming an intrinsic semiconductor layer 13 and an optical adjustment layer 15 in order on one principal surface side of a semiconductor substrate 11, a step for forming sacrificial layers 41, 43 on the optical adjustment layer 15, a step for forming a patterned first conductive-type semiconductor layer 25 on the other principal surface side of the semiconductor substrate 11, and a step for forming a patterned second conductive-type semiconductor layer on the other principal surface side of the semiconductor substrate 11, wherein the sacrificial layers 41, 43 protect the intrinsic semiconductor layer 13 and the optical adjustment layer 15 from a solution for peeling away a photoresist 90 during the first and/or second conductive-type semiconductor layer formation steps, while the sacrificial layers are partially removed during the first or second conductive-type semiconductor layer formation step or the electrode layer formation step, and are completely removed after the electrode layer formation step

Method for producing solar cells

This method involves: a step for forming a first semiconductor layer (13p) of a first conductive type on one principal surface of a crystal substrate (11); a step for layering a first lift-off layer (LF1) and a second lift-off layer (LF2) which contain silicon and have different densities on the first semiconductor layer; a step for selectively removing the first and second lift-off layers and the first semiconductor layer; a step for forming a second semiconductor layer (13n) of a second conductive type on the one principal surface containing the first and second lift-off layers and the first semiconductor layer; and a step for removing the second semiconductor layer which covers the second lift-off layer by removing the first and second lift-off layers using a first etching solution The etching speeds of the first semiconductor layer and the first and second lift-off layers when subjected to the first etching solution satisfy formula (1): first semiconductor layer etching speed < second lift-off layer etching speed < first lift-off layer etching speed

Method for producing solar cell

PROBLEM TO BE SOLVED: To provide a method of manufacturing a crystal silicon solar cell of high conversion efficiency, in which the absorption loss due to reduction of a transparent electrode layer is suppressed.SOLUTION: A method of manufacturing a solar cell having a photoelectric conversion part, and a first transparent electrode layer principally composed of indium oxide, and a collector electrode including a plating layer, in this order, on the first principal surface of the photoelectric conversion part, has an insulating layer formation step of forming an insulating layer principally composed of silicon nitride on the first principal surface of a first transparent electrode layer by CVD, and a step of forming a plating layer at the opening of the insulating layer by plating, in this order. The manufacturing method has a blackening prevention layer formation step for forming a blackening prevention layer on the substantially entire surface of a collector electrode non-formation region on the first principal surface of the first transparent electrode layer.SELECTED DRAWING: Figure 1

Daisuke Adachi

Papers

Solar cell manufacturing method

Method for producing solar cells

Method for producing solar cell

Crystal silicon solar cell and method of manufacturing the same, and solar cell module

Production method for a solar cell