Back interface passivation reduces the back recombination of photogenerated electrons, whereas aggravates the blocking of hole transport towards back contact, which complicate the back interface engineering for ultrat...Back interface passivation reduces the back recombination of photogenerated electrons, whereas aggravates the blocking of hole transport towards back contact, which complicate the back interface engineering for ultrathin CIGSe solar cells with a Schottky back contact. In this work, theoretical explorations were conducted to study how the two contradictory electrical effects impact cell performance. For ultrathin CIGSe solar cells with a pronounced Schottky potential barrier(E_(h)> 0.2 eV), back interface passivation produces diverse performance evolution trends, which are highly dependent on cell structures and properties. Since a back Ga grading can screen the effect of reduced recombination of photogenerated electrons from back interface passivation, the hole blocking effect predominates and back interface passivation is not desirable. However, when the back Schottky diode merges with the main pn junction due to a reduced absorber thickness,the back potential barrier and the hole blocking effect is much reduced on this occasion. Consequently, cells exhibit the same efficiency evolution trend as ones with an Ohmic contact, where back interface passivation is always advantageous.The discoveries imply the complexity of back interface passivation and provide guidance to manipulate back interface for ultrathin CIGSe solar on TCOs with a pronounced Schottky back contact.展开更多
SnO_(2)is widely used as the electron transport layer(ETL)in perovskite solar cells(PSCs)due to its excellent electron mobility,low processing temperature,and low cost.And the most common way of preparing the SnO_(2)E...SnO_(2)is widely used as the electron transport layer(ETL)in perovskite solar cells(PSCs)due to its excellent electron mobility,low processing temperature,and low cost.And the most common way of preparing the SnO_(2)ETL is spincoating using the corresponding colloid solution.However,the spin-coated SnO_(2)layer is sometimes not so compact and contains pinholes,weakening the hole blocking capability.Here,a SnO_(2)thin film prepared through magnetron-sputtering was inserted between ITO and the spin-coated SnO_(2)acted as an interlayer.This strategy can combine the advantages of efficient electron extraction and hole blocking due to the high compactness of the sputtered film and the excellent electronic property of the spin-coated SnO_(2).Therefore,the recombination of photo-generated carriers at the interface is significantly reduced.As a result,the semitransparent perovskite solar cells(with a bandgap of 1.73 eV)based on this double-layered SnO_(2)demonstrate a maximum efficiency of 17.7%(stabilized at 17.04%)with negligible hysteresis.Moreover,the shelf stability of the device is also significantly improved,maintaining 95%of the initial efficiency after 800-hours of aging.展开更多
The properties of top-contact organic thin-film transistors （TC-OTFTs） using ultra-thin 2, 9-dimethyl-4, 7- diphenyl-1, 10-phenanthroline （BCP） as a hole-blocking interlayer have been improved significantly and a ...The properties of top-contact organic thin-film transistors （TC-OTFTs） using ultra-thin 2, 9-dimethyl-4, 7- diphenyl-1, 10-phenanthroline （BCP） as a hole-blocking interlayer have been improved significantly and a BCP interlayer was inserted into the middle of the pentacene active layer. This paper obtains a fire-new transport mode of an OTFT device with double-conductible channels. The accumulation and transfer of the hole carriers arc limited by the BCP interlayer in the vertical region of the channel. A huge amount of carriers is located not only at the interface between pentacene and the gate insulator, but also at the two interfaces of pentacene/BCP interlayer and pentacene/gate insulator, respectively. The results suggest that the BCP interlayer may be useful to adjust the hole accumulation and transfer, and can increase the hole mobility and output current of OTFTs. The TC-OTFTs with a BCP interlayer at VDS = --20 V showed excellent hole mobility μFE and threshold voltage VTH of 0.58 cm^2/（V-s） and -4.6 V, respectively.展开更多
采用N,N'-二正辛烷基-3,4,9,10-苝四甲酰二亚胺(PTCDI-C8)对钙钛矿电池电子传输层(PCBM)进行界面修饰以减少PCBM与Al电极之间的漏电流,提高阴极的电子收集效率。通过调节PTCDI-C8薄膜的厚度优化界面接触和电子传输性能。实验结果表...采用N,N'-二正辛烷基-3,4,9,10-苝四甲酰二亚胺(PTCDI-C8)对钙钛矿电池电子传输层(PCBM)进行界面修饰以减少PCBM与Al电极之间的漏电流,提高阴极的电子收集效率。通过调节PTCDI-C8薄膜的厚度优化界面接触和电子传输性能。实验结果表明:当PTCDI-C8薄膜的厚度为20 nm时得到的器件性能最优。光电转换效率(PCE)由5.26%提高到了8.65%,开路电压(Voc)为0.92 V,短路电流(Jsc)为15.68 m A/cm2,填充因子(FF)为60%。PTCDI-C8能够有效阻挡空穴向阴极传输,同时PTCDI-C8具有较高的电子迁移率以及较高的稳定性,在增加电子传输的同时,可减少环境对PCBM的侵蚀,提高了器件的稳定性。展开更多
We report a simple hole-blocking material （biphenyl-3,3＇-diyl）bis（diphenylphosphine oxide） （BiPh-m-BiDPO） based on our recent advance. The bis（phosphine oxide） compound shows HOMO/LUMO levels of ∽-6.71/- 2.5...We report a simple hole-blocking material （biphenyl-3,3＇-diyl）bis（diphenylphosphine oxide） （BiPh-m-BiDPO） based on our recent advance. The bis（phosphine oxide） compound shows HOMO/LUMO levels of ∽-6.71/- 2.51 eV. Its phosphorescent spectrum in a solid film features two major emission bands peaking at 2.69 and 2.4eV, corresponding to 0-0 and 01 vibronic transitions, respectively. The measurement of the electron-only devices reveals that BiPh-m-BiDPO possesses electron mobility of 2.28 × 10^-9-3.22× 10^-8cm2 V-1s-1 at E = 2- 5 × 10^5 V/cm. The characterization of the sky blue fluorescent and red phosphorescent pin organic light-emitting diodes （OLEDs） utilizing BiPh-m-BiDPO as the hole blocker shows that its shallow LUMO level as well as the low electron mobility affects significantly the power efficiency and hence operational stability, relative to the luminous efficiency, especially at high luminance. In combination with our recent results, the present study provides an indepth insight on the molecular structure-property correlation in the organic phosphinyl-containing hole-blocking materials.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 51802240)。
文摘Back interface passivation reduces the back recombination of photogenerated electrons, whereas aggravates the blocking of hole transport towards back contact, which complicate the back interface engineering for ultrathin CIGSe solar cells with a Schottky back contact. In this work, theoretical explorations were conducted to study how the two contradictory electrical effects impact cell performance. For ultrathin CIGSe solar cells with a pronounced Schottky potential barrier(E_(h)> 0.2 eV), back interface passivation produces diverse performance evolution trends, which are highly dependent on cell structures and properties. Since a back Ga grading can screen the effect of reduced recombination of photogenerated electrons from back interface passivation, the hole blocking effect predominates and back interface passivation is not desirable. However, when the back Schottky diode merges with the main pn junction due to a reduced absorber thickness,the back potential barrier and the hole blocking effect is much reduced on this occasion. Consequently, cells exhibit the same efficiency evolution trend as ones with an Ohmic contact, where back interface passivation is always advantageous.The discoveries imply the complexity of back interface passivation and provide guidance to manipulate back interface for ultrathin CIGSe solar on TCOs with a pronounced Schottky back contact.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.22179042,U21A2078,and 51902110)the Natural Science Foundation of Fujian Province,China(Grant Nos.2020J06021,2019J01057,and 2020J01064)+1 种基金Scientific Research Funds of Huaqiao UniversityPromotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University(Grant Nos.ZQN-PY607 and ZQN-806)。
文摘SnO_(2)is widely used as the electron transport layer(ETL)in perovskite solar cells(PSCs)due to its excellent electron mobility,low processing temperature,and low cost.And the most common way of preparing the SnO_(2)ETL is spincoating using the corresponding colloid solution.However,the spin-coated SnO_(2)layer is sometimes not so compact and contains pinholes,weakening the hole blocking capability.Here,a SnO_(2)thin film prepared through magnetron-sputtering was inserted between ITO and the spin-coated SnO_(2)acted as an interlayer.This strategy can combine the advantages of efficient electron extraction and hole blocking due to the high compactness of the sputtered film and the excellent electronic property of the spin-coated SnO_(2).Therefore,the recombination of photo-generated carriers at the interface is significantly reduced.As a result,the semitransparent perovskite solar cells(with a bandgap of 1.73 eV)based on this double-layered SnO_(2)demonstrate a maximum efficiency of 17.7%(stabilized at 17.04%)with negligible hysteresis.Moreover,the shelf stability of the device is also significantly improved,maintaining 95%of the initial efficiency after 800-hours of aging.
基金supported by the National High Technology Research and Development Program of China (Grant No 2006AA03Z0412)the National Natural Science Foundation of China (Grant Nos 10774013 and 10804006)+4 种基金the Excellent Doctor’s Science and Technology Innovation Foundation of Beijing Jiaotong University (Grant No 48024)the Foundation of Beijing Jiaotong University (Grant No 2005SM057)the Research Fund for the Youth Scholars of the Doctoral Program of Higher Education (Grant No 20070004031)the Beijing NOVA program (Grant No 2007A024)Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘The properties of top-contact organic thin-film transistors （TC-OTFTs） using ultra-thin 2, 9-dimethyl-4, 7- diphenyl-1, 10-phenanthroline （BCP） as a hole-blocking interlayer have been improved significantly and a BCP interlayer was inserted into the middle of the pentacene active layer. This paper obtains a fire-new transport mode of an OTFT device with double-conductible channels. The accumulation and transfer of the hole carriers arc limited by the BCP interlayer in the vertical region of the channel. A huge amount of carriers is located not only at the interface between pentacene and the gate insulator, but also at the two interfaces of pentacene/BCP interlayer and pentacene/gate insulator, respectively. The results suggest that the BCP interlayer may be useful to adjust the hole accumulation and transfer, and can increase the hole mobility and output current of OTFTs. The TC-OTFTs with a BCP interlayer at VDS = --20 V showed excellent hole mobility μFE and threshold voltage VTH of 0.58 cm^2/（V-s） and -4.6 V, respectively.
基金Supported by National Natural Science Foundation of China(5140221461504097)Natural Science Foundation of Tianjin(17JCYBJC21000)~~
文摘采用N,N'-二正辛烷基-3,4,9,10-苝四甲酰二亚胺(PTCDI-C8)对钙钛矿电池电子传输层(PCBM)进行界面修饰以减少PCBM与Al电极之间的漏电流,提高阴极的电子收集效率。通过调节PTCDI-C8薄膜的厚度优化界面接触和电子传输性能。实验结果表明:当PTCDI-C8薄膜的厚度为20 nm时得到的器件性能最优。光电转换效率(PCE)由5.26%提高到了8.65%,开路电压(Voc)为0.92 V,短路电流(Jsc)为15.68 m A/cm2,填充因子(FF)为60%。PTCDI-C8能够有效阻挡空穴向阴极传输,同时PTCDI-C8具有较高的电子迁移率以及较高的稳定性,在增加电子传输的同时,可减少环境对PCBM的侵蚀,提高了器件的稳定性。
基金Supported by the National Natural Science Foundation of China under Grant No U1301243the National Key Research and Development Program of China under Grant No 2016YFB0400701
文摘We report a simple hole-blocking material （biphenyl-3,3＇-diyl）bis（diphenylphosphine oxide） （BiPh-m-BiDPO） based on our recent advance. The bis（phosphine oxide） compound shows HOMO/LUMO levels of ∽-6.71/- 2.51 eV. Its phosphorescent spectrum in a solid film features two major emission bands peaking at 2.69 and 2.4eV, corresponding to 0-0 and 01 vibronic transitions, respectively. The measurement of the electron-only devices reveals that BiPh-m-BiDPO possesses electron mobility of 2.28 × 10^-9-3.22× 10^-8cm2 V-1s-1 at E = 2- 5 × 10^5 V/cm. The characterization of the sky blue fluorescent and red phosphorescent pin organic light-emitting diodes （OLEDs） utilizing BiPh-m-BiDPO as the hole blocker shows that its shallow LUMO level as well as the low electron mobility affects significantly the power efficiency and hence operational stability, relative to the luminous efficiency, especially at high luminance. In combination with our recent results, the present study provides an indepth insight on the molecular structure-property correlation in the organic phosphinyl-containing hole-blocking materials.
