Novel Intense-pulsed-light synthesis of amorphous SnO_(2)electron-selective layers for efficient planar MAPbI_(3)perovskite solar cells

Although perovskite solar cells(PSCs)have achieved a high power conversion efficiency(PCE)within a short period of development,the high-temperature sintering of the constituent electron-selective layers(ESLs)impedes the commercialization.In this report,we demonstrate the effectiveness of an intensepulsed-light(IPL)treatment for the rapid and damage-free sintering of amorphous-SnO_(2)ESLs for use in PSCs.The IPL treatment of amorphous-SnO_(2)substantially reduced the amount of surface hydroxyl groups,modified the surface energy,and enabled the growth of a low-stress perovskite layer with large grain sizes,all of which enhanced the photovoltaic properties and led to the proper alignment of band structures for efficient PSCs.Through comprehensive optimization of the IPL conditions,a PCE of 17.68%was achieved from the MAPb I3 planar PSC based on an amorphous-SnO_(2)IPL treated for a few tens of seconds,which was significantly increased compared with a PCE(7.06%)of nontreated SnO_(2)based counterpart.In addition,the PCE of the IPL-treated SnO_(2)based PSC is comparable to the best PCE(18.16%)of PSCs fabricated with SnO_(2)ESL annealed for three hours at 185℃.Because of its ultrafast sintering time and tendency to not damage SnO_(2)ESLs,the new IPL process is expected to open new opportunities for the commercialization of PSCs.

High-performance SiO_(x)/MgO_(x)electron-selective contacts for crystalline silicon solar cells

High carrier recombination loss at the metal and silicon contact regions is one of the dominant factors constraining the power conversion efficiency(PCE)of crystalline silicon(c-Si)solar cells.Metal compound-based carrier-selective contacts are being intensively developed to address this issue.In this work,we present a high-performance electron-selective SiO_(x)/MgO_(x)contact for c-Si solar cells.The SiO_(x)/MgO_(x)stack is prepared by thermally-grown SiO_(x)(∼0.7 nm)and thermally-evaporated MgO_(x)(~1.0 nm).The electron selectivity of SiO_(x)/MgO_(x)contact is investigated by measuring the surface passivation and the contact resistivity(ρ_(c))on the c-Si surface.The results demonstrate that optimized SiO_(x)/MgO_(x)contact displays a very lowρ_(c)(3.4 mΩcm^(2))and a good surface passivation on an n-type c-Si surface simultaneously.A high PCE of 21.1%is achieved on an n-type c-Si solar cell featuring a full-area SiO_(x)/MgO_(x)rear contact.

A sintering-free, nanocrystalline tin oxide electron selective layer for organometal perovskite solar cells

Effective electron selective layer （ESL） is critical for the power conversion efficiency in organometal halide- based perovskite solar cells （PSCs）. In this work, a spincoating process has been developed to fabricate high quality nanocrystalline SnO2 film at 100℃ without further sintering at higher temperature. When used as ESL in PSCs, such SnO2 film shows greater electron extraction ability and higher efficiency than TiO2 film processed under similar condition, as evidenced by the efficient time-resolved photoluminescence （TRPL） quenching SnO2/CH3NH3PbI3 film. As a resuit, the SnO2-based PSCs possess higher open circuit voltage of 0.91 V, short circuit current density of 20.73 mA cm^-2, and fill factor of 64.25%, corresponding to a conversion efficiency of 12.10%, compared with 7.16% of TiO2-based PSCs. This demonstrates the great potential of applying spin-coating sintering-free process for the low-cost and large-scale manufacturing of PSCs.