The interface between the active layer and the electrode is one of the most critical factors that could affect the device performance of polymer solar cells. In this work, based on the typical poly（3-hexylthiophene）...The interface between the active layer and the electrode is one of the most critical factors that could affect the device performance of polymer solar cells. In this work, based on the typical poly（3-hexylthiophene）：[6,6]-phenyl C61-butyric acid methyl ester （P3HT：PCBM） polymer solar cell, we studied the effect of the cathode buffer layer （CBL） between the top metal electrode and the active layer on the device performance. Several inorganic and organic materials commonly used as the electron injection layer in an organic light-emitting diode （OLED） were employed as the CBL in the P3HT：PCBM polymer solar cells. Our results demonstrate that the inorganic and organic materials like Cs2CO3, bathophenanthroline （Bphen）, and 8-hydroxyquinolatolithium （Liq） can be used as CBL to efficiently improve the device performance of the P3HT：PCBM polymer solar cells. The P3HT：PCBM devices employed various CBLs possess power conversion efficiencies （PCEs） of 3.0%-3.3%, which are ca. 50% improved compared to that of the device without CBL. Furthermore, by using the doped organic materials Bphen：Cs2CO3 and Bphen：Liq as the CBL, the PCE of the P3HT：PCBM device will be further improved to 3.5%, which is ca. 70% higher than that of the device without a CBL and ca. 10% increased compared with that of the devices with a neat inorganic or organic CBL.展开更多
We have improved the photovoltaic performance of 2,4-bis[4-（N,N- diisobutylamino）-2,6-dihydroxyphenyl] squaraine：[6,6]-phenyl C71-butyric acid methyl ester （DIBSQ：PC71BM） organic photovoltaic （OPV） cells via i...We have improved the photovoltaic performance of 2,4-bis[4-（N,N- diisobutylamino）-2,6-dihydroxyphenyl] squaraine：[6,6]-phenyl C71-butyric acid methyl ester （DIBSQ：PC71BM） organic photovoltaic （OPV） cells via incorporating Liq-doped Bphen （Bphen-Liq） as a cathode buffer layer （CBL）. Based on the Bphen-Liq CBL, a DIBSQ：PC71BM OPV cell possessed an optimal power conversion efficiency of 4.90%, which was 13% and 60% higher than those of the devices with neat Bphen as CBL and without CBL, respectively. The enhancement of the device performance could be attributed to the enhanced electron mobility and improved electrode/active layer contact and thus the improved photocurrent extraction by incorporating the Bphen-Liq CBL. Light-intensity dependent device performance analysis indicates that the incorporating of the Bphen-Liq CBL can remarkably improve the charge transport of the DIBSQ：PC71BM OPV cell and thus decrease the recombination losses of the device, resulting in enhanced device performance. Our finding indicates that the doped Bphen-Liq CBL has great potential for high-performance solution-processed small-molecule OPVs.展开更多
This article presents the investigation on very thin Lanthanum Fluoride (LaF3) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl...This article presents the investigation on very thin Lanthanum Fluoride (LaF3) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) polymer blend at 1:1 ratio. Electron-beam evaporation at room temperature was used to deposit 3 and 5 nm thick LaF3 layer. A very smooth surface of LaF3 with an average roughness of 0.2 nm has been observed by the Atomic Force Microscope (AFM) that is expected to prevent diffusion of cathode metal ion through it and thereby enhance the lifetime and stability of OSC. Huge enhancement of JSC and VOC was also observed for 3 nm-thick LaF3 CBL. Several excellent features of the LaF3 layer such as, transporting electron through tunneling, blocking of holes to the cathode, minimizing recombination, protecting the photoactive polymer from ambient oxygen, and reducing degradation/oxidation of any low work function layer at the cathode interface, might have contributed to the performance enhancement of OSC. The experimental findings indicate the promise of LaF3 to be an excellent CBL material for OSC.展开更多
Facile synthesis of an interfacial layer in organic solar cells (OSCs) is important for broadening material designs and upscaling photovoltaic conversion efficiency (PCE).Herein,a mild solution process of spin-coating...Facile synthesis of an interfacial layer in organic solar cells (OSCs) is important for broadening material designs and upscaling photovoltaic conversion efficiency (PCE).Herein,a mild solution process of spin-coating In(acac)3and Ga(acac)3isopropanol precursors followed by low-temperature thermal treatment was developed to fabricate In_(2)O_(3)and Ga2O3cathode buffer layers (CBLs).The introduction of In_(2)O_(3)or Ga2O3CBLs endows PM6:Y6-based OSCs with outstanding performance and high PCEs of 16.17%and 16.01%,respectively.Comparison studies present that the In_(2)O_(3)layer possesses a work function (WF) of 4.58 eV,which is more favorable for the formation of ohmic contact compared with the Ga2O3layer with a WF of 5.06 eV and leads to a higher open circuit voltage for the former devices.Electrochemical impedance spectroscopy was performed to reveal how In_(2)O_(3)and Ga2O3affect the internal charge transfer and the origin of their performance difference.Although In_(2)O_(3)possesses lower series resistance loss,Ga2O3has a higher recombination resistance,which enhances the device fill factor and compensates for its series resistance loss to some extent.Comparative analysis of the photo-physics of In_(2)O_(3)and Ga2O3suggests that both are excellent CBLs for highly efficient OSCs.展开更多
An electron transporting material of TFTTP （4-（5-hexylthiophene-2-yl）-2,6-bis（5-trifluoromethyl）thiophen-2-yl）pyridine） was investigated as a cathode buffer layer to enhance the power efficiency of organic sola...An electron transporting material of TFTTP （4-（5-hexylthiophene-2-yl）-2,6-bis（5-trifluoromethyl）thiophen-2-yl）pyridine） was investigated as a cathode buffer layer to enhance the power efficiency of organic solar cells （OSCs） based on subphthalocyanine and C60. The overall power conversion efficiency was increased by a factor of 1.31 by inserting the TFTTP interfacial layer between the active layer and metallic cathode. The inner mechanism responsible for the performance enhancement of OSCs was systematically studied with the simulation of dark diode behavior and optical field distribution inside the devices as well as the characterization of device photocurrent. The results showed that the TFTTP layer could significantly increase the built-in potential in the devices, leading to the enhanced dissociation of charge transfer excitons. In addition, by using TFTTP as the buffer layer, a better Ohmic contact at C60/metal interface was formed, facilitating more efficient free charge carrier collection.展开更多
An inexpensive material, i.e., tetranuclear zinc（Ⅱ） complex, （Zn40（A/D）6） [AID = 7-azaindolate], was utilized as a cathode buffer in organic photovoltaic （OPV） devices, leading to the improvement of device pe...An inexpensive material, i.e., tetranuclear zinc（Ⅱ） complex, （Zn40（A/D）6） [AID = 7-azaindolate], was utilized as a cathode buffer in organic photovoltaic （OPV） devices, leading to the improvement of device performance. Compared to OPV devices based on a conventional cathode buffer of TPBi （1,3,5-tris（2-N-phenylbenzimidazolyl）benzene）, although the freshly prepared devices showed similar performance, when heated to a series of high temperatures under air, the short circuit current and the open circuit voltage of the Zn40（AID）6 devices dropped more slowly, indicating the superiority of using Zn40（AID）6 as a cathode buffer over TPBi in OPV devices.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61204014)the“Chenguang”Project(13CG42)+1 种基金supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation,Chinathe Shanghai University Young Teacher Training Program of Shanghai Municipality,China
文摘The interface between the active layer and the electrode is one of the most critical factors that could affect the device performance of polymer solar cells. In this work, based on the typical poly（3-hexylthiophene）：[6,6]-phenyl C61-butyric acid methyl ester （P3HT：PCBM） polymer solar cell, we studied the effect of the cathode buffer layer （CBL） between the top metal electrode and the active layer on the device performance. Several inorganic and organic materials commonly used as the electron injection layer in an organic light-emitting diode （OLED） were employed as the CBL in the P3HT：PCBM polymer solar cells. Our results demonstrate that the inorganic and organic materials like Cs2CO3, bathophenanthroline （Bphen）, and 8-hydroxyquinolatolithium （Liq） can be used as CBL to efficiently improve the device performance of the P3HT：PCBM polymer solar cells. The P3HT：PCBM devices employed various CBLs possess power conversion efficiencies （PCEs） of 3.0%-3.3%, which are ca. 50% improved compared to that of the device without CBL. Furthermore, by using the doped organic materials Bphen：Cs2CO3 and Bphen：Liq as the CBL, the PCE of the P3HT：PCBM device will be further improved to 3.5%, which is ca. 70% higher than that of the device without a CBL and ca. 10% increased compared with that of the devices with a neat inorganic or organic CBL.
基金supported by the National Natural Science Foundation of China(91433202,21773262,21521062,21276059,91227112)the Chinese Academy of Sciences(XDB12010200)~~
基金Acknowledgements This work was financially supported by the National Natural Science Foundation of China （Grant No. 61604093）, the Natural Science Foundation of Shanghai （16ZR1411000）, the Shanghai Pujiang Program （16PJ1403300）, and the Shanghai University Young Teacher Training Program （ZZSD 15049）.
文摘We have improved the photovoltaic performance of 2,4-bis[4-（N,N- diisobutylamino）-2,6-dihydroxyphenyl] squaraine：[6,6]-phenyl C71-butyric acid methyl ester （DIBSQ：PC71BM） organic photovoltaic （OPV） cells via incorporating Liq-doped Bphen （Bphen-Liq） as a cathode buffer layer （CBL）. Based on the Bphen-Liq CBL, a DIBSQ：PC71BM OPV cell possessed an optimal power conversion efficiency of 4.90%, which was 13% and 60% higher than those of the devices with neat Bphen as CBL and without CBL, respectively. The enhancement of the device performance could be attributed to the enhanced electron mobility and improved electrode/active layer contact and thus the improved photocurrent extraction by incorporating the Bphen-Liq CBL. Light-intensity dependent device performance analysis indicates that the incorporating of the Bphen-Liq CBL can remarkably improve the charge transport of the DIBSQ：PC71BM OPV cell and thus decrease the recombination losses of the device, resulting in enhanced device performance. Our finding indicates that the doped Bphen-Liq CBL has great potential for high-performance solution-processed small-molecule OPVs.
文摘This article presents the investigation on very thin Lanthanum Fluoride (LaF3) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) polymer blend at 1:1 ratio. Electron-beam evaporation at room temperature was used to deposit 3 and 5 nm thick LaF3 layer. A very smooth surface of LaF3 with an average roughness of 0.2 nm has been observed by the Atomic Force Microscope (AFM) that is expected to prevent diffusion of cathode metal ion through it and thereby enhance the lifetime and stability of OSC. Huge enhancement of JSC and VOC was also observed for 3 nm-thick LaF3 CBL. Several excellent features of the LaF3 layer such as, transporting electron through tunneling, blocking of holes to the cathode, minimizing recombination, protecting the photoactive polymer from ambient oxygen, and reducing degradation/oxidation of any low work function layer at the cathode interface, might have contributed to the performance enhancement of OSC. The experimental findings indicate the promise of LaF3 to be an excellent CBL material for OSC.
基金supported by the National Natural Science Foundation of China (51573042,61874148,51873007,5181101540 and 21835006)the Fundamental Research Funds for the Central Universities in China (2019MS025 and 2018MS032)the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources (LAPS20003)。
文摘Facile synthesis of an interfacial layer in organic solar cells (OSCs) is important for broadening material designs and upscaling photovoltaic conversion efficiency (PCE).Herein,a mild solution process of spin-coating In(acac)3and Ga(acac)3isopropanol precursors followed by low-temperature thermal treatment was developed to fabricate In_(2)O_(3)and Ga2O3cathode buffer layers (CBLs).The introduction of In_(2)O_(3)or Ga2O3CBLs endows PM6:Y6-based OSCs with outstanding performance and high PCEs of 16.17%and 16.01%,respectively.Comparison studies present that the In_(2)O_(3)layer possesses a work function (WF) of 4.58 eV,which is more favorable for the formation of ohmic contact compared with the Ga2O3layer with a WF of 5.06 eV and leads to a higher open circuit voltage for the former devices.Electrochemical impedance spectroscopy was performed to reveal how In_(2)O_(3)and Ga2O3affect the internal charge transfer and the origin of their performance difference.Although In_(2)O_(3)possesses lower series resistance loss,Ga2O3has a higher recombination resistance,which enhances the device fill factor and compensates for its series resistance loss to some extent.Comparative analysis of the photo-physics of In_(2)O_(3)and Ga2O3suggests that both are excellent CBLs for highly efficient OSCs.
文摘An electron transporting material of TFTTP （4-（5-hexylthiophene-2-yl）-2,6-bis（5-trifluoromethyl）thiophen-2-yl）pyridine） was investigated as a cathode buffer layer to enhance the power efficiency of organic solar cells （OSCs） based on subphthalocyanine and C60. The overall power conversion efficiency was increased by a factor of 1.31 by inserting the TFTTP interfacial layer between the active layer and metallic cathode. The inner mechanism responsible for the performance enhancement of OSCs was systematically studied with the simulation of dark diode behavior and optical field distribution inside the devices as well as the characterization of device photocurrent. The results showed that the TFTTP layer could significantly increase the built-in potential in the devices, leading to the enhanced dissociation of charge transfer excitons. In addition, by using TFTTP as the buffer layer, a better Ohmic contact at C60/metal interface was formed, facilitating more efficient free charge carrier collection.
基金supported by the National Natural Science Foundation of China(20974046,61077021,61076016)New Century Excellent Talents funding from Ministry of Education in China(NCET-08-0697)National Basic Research Program of China(973 Program,2009CB930600)
文摘An inexpensive material, i.e., tetranuclear zinc（Ⅱ） complex, （Zn40（A/D）6） [AID = 7-azaindolate], was utilized as a cathode buffer in organic photovoltaic （OPV） devices, leading to the improvement of device performance. Compared to OPV devices based on a conventional cathode buffer of TPBi （1,3,5-tris（2-N-phenylbenzimidazolyl）benzene）, although the freshly prepared devices showed similar performance, when heated to a series of high temperatures under air, the short circuit current and the open circuit voltage of the Zn40（AID）6 devices dropped more slowly, indicating the superiority of using Zn40（AID）6 as a cathode buffer over TPBi in OPV devices.
