Perovskite materials offer a great potential in the application of semitransparent solar cells, owing to the tunable bandgap, ease of preparation and excellent photovoltaic property. A majority of works exhibit high average visible‐light transmittance (AVT) for semitransparent perovskite solar cells (ST‐PSCs) through decreasing perovskite thickness, leading to sacrificing the power conversion efficiency (PCE) of the device. Herein, a wide‐bandgap (WBG) perovskite of Cs0.2FA0.8Pb(I0.6Br0.4)3 is applied as absorber in ST‐PSCs, which is a tremendous progress to balance both large PCE and high AVT. Moreover, a strategy of simultaneous interfacial modification and defect passivation is provided to enhance the performance of WBG ST‐PSCs. Consequently, an inverted planar structure WBG perovskite solar cell (PSC) achieves 15.06% of PCE with excellent stability by restraining the interfacial energy loss and suppressing the nonradiative recombination. Furthermore, the ST‐PSC obtains high PCE of 14.40% with an AVT of 38% by means of optimizing the transparent electrode. This work provides an efficient and simple method to improve the performance and AVT of ST‐PSCs for the application in building‐integrated photovoltaics.

Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 10/05/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Abstract. A fast and effective algorithm for designing the diffraction optical element (DOE) with a wide-diffraction angle is presented. DOE had been widely used in many fields in recent years, but there are finite methods which can design DOE with wide-diffraction angle quickly occupying a small quantity of computing resource. By the use of a nonparaxial scalar diffraction equation as the light transmission operator, a modified iterative algorithm is proposed. To verify our algorithm, the checkerboard image, binary image, and gray-scale image are numerically simulated, respectively. The simulation results show that the final variance between the preset image and final pattern is very small, the value is generally lower than 10 −5 , and the natural images even have a final variance less than 10 −12 . At the same time, the diffraction efficiency has been significantly increased to be larger than 90%, which indicates that the design method is effective and practical. Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 10/05/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Optical Engineering 093106-7 September 2015 • Vol. 54(9) Lv et al.: Modified iterative algorithm for the design of wide-diffraction angle diffraction optical element Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 10/05/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx