Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has a...Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.展开更多
Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between...Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between a module's constituent cells where the substrate-side charge transport layer(CTL)is in direct contact with SLG.Na diffusion from SLG is known to cause several important effects inⅡ-Ⅵand chalcogenide solar modules,but it has not been studied in perovskite solar modules(PSMs).In this work,we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of PSMs.Na diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 pm.We propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite annealing.The diffused Na preferentially binds with Br,forming Br-poor,l-rich perovskite and a species rich in Na and Br(Na-Br)close to P1 lines.Na-Br passivates defect sites,reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5×.Na-Br is observed to be stable after 12 weeks of device storage,suggesting long-lasting effects of Na diffusion.Our results not only point to a potential avenue to increase PSM performance but also highlight the possibility of unabated Na diffusion throughout a module's lifetime,especially if accelerated by the electric field and elevated temperatures achievable during device operation.展开更多
Efficient flexible perovskite solar cells and modules were developed using a combination of SnO2 and mesoporous-TiO2 as a fully solution-processed electron transport layer （ETL）. Cells using such ETLs delivered a ma...Efficient flexible perovskite solar cells and modules were developed using a combination of SnO2 and mesoporous-TiO2 as a fully solution-processed electron transport layer （ETL）. Cells using such ETLs delivered a maximum power conversion efficiency （PCE） of 14.8%, which was 30% higher than the PCE of cells with only SnO2 as the ETL. The presence of a mesoporous TiO2 scaffold layer over SnO2 led to higher rectification ratios, lower series resistances, and higher shunt resistances. The cells were also evaluated under 200 and 400 lx artificial indoor illumination and found to deliver maximum power densities of 9.77 μW/cm^2 （estimated PCE of 12.8%） and 19.2 μW/cm^2 （estimated PCE of 13.3%）, respectively, representing the highest values among flexible photovoltaic technologies reported so far. Furthermore, for the first time, a fully laser-patterned flexible perovskite module was fabricated using a complete three-step laser scribing procedure （P1, P2, P3） with a PCE of 8.8% over an active area of 12 cm^2 under an illumination of 1 sun.展开更多
基金supported by the project“PARIDE”(Perovskite Advanced Radiotherapy&Imaging Detectors),funded under the Regional Research and Innovation Programme POR-FESR Lazio 2014-2020(project number:A0375-2020-36698).
文摘Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.
基金the Jardine Foundation and Cambridge Trust for a doctoral scholarshipthe European Union(EU)Horizon 2020 research and innovation program under grant No.764047(ESPResSo)+12 种基金funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No.823717-ESTEEM3.J.F.Oacknowledges funding from the Engineering and Physical Sciences Research Council(EPSRC)Nano Doctoral Training Centre(EP/L015978/1)J.F.O.,G.K.,and R.A.O.acknowledge Attolight and EPSRC(EP/R025193/1)for funding and supporting the SEM-CL systemE.M.T.thanks the EU Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no.841265.S.D.S.E.M.T.acknowledge funding from the EPSRC(EP/R023980/1)the EPSRC Centre for Advanced Materials for Integrated Energy Systems(CAM-IES,EP/P007767/1)Cambridge Royce facilities grant(EP/P024947/1)S.D.S.acknowledges funding from the Royal Society and Tata Group(UF150033)from the European Research Council under the EU Horizon 2020 research and innovation program under grant No.756962(HYPERION)W.L.and J.L.M.-D.acknowledge support from the EPSRC(EP/L011700/1,EP/N004272/1)the Leverhulme Trust(RPG-2015-017)the Royal Academy of Engineering Chair in Emerging Technologies(CiET1819_24)We wish to acknowledge the support of the Henry Royce Institute(HRI)for F.U.K.through the Royce PhD Equipment Access Scheme enabling access to the NanoSIMS facility at Manchester.The NanoSIMS was funded by UK Research Partnership Investment Funding(UKRPIF)Manchester RPIF Round 2.This work was supported by the HRI,funded through EPSRC grants EP/R00661X/1,EP/S019367/1,EP/P025021/1,and EP/P025498/1
文摘Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between a module's constituent cells where the substrate-side charge transport layer(CTL)is in direct contact with SLG.Na diffusion from SLG is known to cause several important effects inⅡ-Ⅵand chalcogenide solar modules,but it has not been studied in perovskite solar modules(PSMs).In this work,we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of PSMs.Na diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 pm.We propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite annealing.The diffused Na preferentially binds with Br,forming Br-poor,l-rich perovskite and a species rich in Na and Br(Na-Br)close to P1 lines.Na-Br passivates defect sites,reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5×.Na-Br is observed to be stable after 12 weeks of device storage,suggesting long-lasting effects of Na diffusion.Our results not only point to a potential avenue to increase PSM performance but also highlight the possibility of unabated Na diffusion throughout a module's lifetime,especially if accelerated by the electric field and elevated temperatures achievable during device operation.
文摘Efficient flexible perovskite solar cells and modules were developed using a combination of SnO2 and mesoporous-TiO2 as a fully solution-processed electron transport layer （ETL）. Cells using such ETLs delivered a maximum power conversion efficiency （PCE） of 14.8%, which was 30% higher than the PCE of cells with only SnO2 as the ETL. The presence of a mesoporous TiO2 scaffold layer over SnO2 led to higher rectification ratios, lower series resistances, and higher shunt resistances. The cells were also evaluated under 200 and 400 lx artificial indoor illumination and found to deliver maximum power densities of 9.77 μW/cm^2 （estimated PCE of 12.8%） and 19.2 μW/cm^2 （estimated PCE of 13.3%）, respectively, representing the highest values among flexible photovoltaic technologies reported so far. Furthermore, for the first time, a fully laser-patterned flexible perovskite module was fabricated using a complete three-step laser scribing procedure （P1, P2, P3） with a PCE of 8.8% over an active area of 12 cm^2 under an illumination of 1 sun.
