Power conversion efficiency(PCE) of quantum dot-sensitized solar cells(QDSSCs) was boosted in a TiO_2 composite film(TCSF) with delicate design in structure where TiO_2 hierarchical porous film(THPF) situated on the t...Power conversion efficiency(PCE) of quantum dot-sensitized solar cells(QDSSCs) was boosted in a TiO_2 composite film(TCSF) with delicate design in structure where TiO_2 hierarchical porous film(THPF) situated on the top of TiO_2 nanorod arrays film(TNAF). In this case, TNAF could supply efficient scattering centers for high light harvesting and direct electrical pathways for fast electron transfer while the THPF could offer porous channels for loading high quantity of previously synthetized quantum dots(QDs) and facilitate the penetration of electrolyte. Meanwhile, in this specific configuration, the presence of anatase–rutile heterojunction at the interface could help the rutile TNAF layer to efficiently collect photo-injected electrons from the anatase THPF layer thus suppressing the recombination of electrons and holes in electrolyte. The results showed that the PCE of QDSSC based on the TNAF photoanode was about 1.4-fold higher(η = 3.05%, J_(sc)= 15.86 m A cm^(-2), V_(oc)= 0.602 V, FF = 0.319) than that of device based on pure THPF(η = 2.20%, J_(sc)= 13.82 m A cm^(-2), V_(oc)= 0.572 V, FF = 0.278).展开更多
The modification of polysulfide electrolyte with additives has been demonstrated as an effective way to improve the photovoltaic performance of quantum dot-sensitized solar cells(QDSCs). Most of these additives can in...The modification of polysulfide electrolyte with additives has been demonstrated as an effective way to improve the photovoltaic performance of quantum dot-sensitized solar cells(QDSCs). Most of these additives can inhibit the charge recombination processes at photoanode/electrolyte interface and favor the improvement of V oc of cell devices. Herein, we showed that the incorporation of elemental selenium(Se) in polysulfide electrolyte to form polyselenosulfide species can notably improve the performance of QDSCs. Unlike previous reports, we present here an integrated investigation of the effects of polyselenosulfide species in polysulfide electrolyte on the photovoltaic performance of QDSCs from both of the photoanode and counter electrode(CE) aspects. Electrochemical impedance spectroscopy(IS) and opencircuit voltage-decay(OCVD) measurements demonstrated that the introduction of Se into polysulfide electrolyte can not only retard charge recombination at photoanode/electrolyte interface, but also reduce the charge transfer resistance at CE/electrolyte interface, resulting in the improvement of J sc and FF values. Consequently, the average efficiency of Zn-Cu-In-Se QDSCs was improved from 9.26% to 9.78% under AM 1.5 G full one sun illumination.展开更多
To pursue electron-generation stability with no sacrifice of photovoltaic performance has been a persistent objective for all kinds of solar cells. Here, we demonstrate the experimental realization of this objective b...To pursue electron-generation stability with no sacrifice of photovoltaic performance has been a persistent objective for all kinds of solar cells. Here, we demonstrate the experimental realization of this objective by quasi-solid-state quantum dot-sensitized solar cells from a series of conducting gel electrolytes composed of polyacrylamide（PAAm） matrix and conductive polymers [polyaniline（PANi）, polypyrrole（PPy） or polythiophene（PT）]. The reduction of Sx2- occurred in both interface and three dimensional framework of conducting gel electrolyte as a result of the electrical conduction of PANi, PPy and PT toward refluxed electrons from external circuit to Pt electrode. The resulting solar cells can yield the solarto-electrical conversion efficiency of 2.33%, 2.25% and 1.80% for PANi, PPy and PT based gel electrolytes,respectively. Those solar cells possessed much higher efficiency than that of 1.74% based on pure PAAm gel electrolyte owing to the enhanced kinetics for Sx2- ？ S2- conversion. More importantly, the stability of quasi-solid-state solar cell is significantly advanced, arising from the localization of liquid electrolyte into the three dimensional framework and therefore reduced leakage and volatilization.展开更多
基金financially supported by the China Postdoctoral Science Foundation(2015M572210,2016M602376)the National Natural Science Foundation of China(61604110)+1 种基金the Hubei Natural Science Foundation of China(2017CFB291)the Foundation of Wuhan University of Science and Technology(2016XZ002)
文摘Power conversion efficiency(PCE) of quantum dot-sensitized solar cells(QDSSCs) was boosted in a TiO_2 composite film(TCSF) with delicate design in structure where TiO_2 hierarchical porous film(THPF) situated on the top of TiO_2 nanorod arrays film(TNAF). In this case, TNAF could supply efficient scattering centers for high light harvesting and direct electrical pathways for fast electron transfer while the THPF could offer porous channels for loading high quantity of previously synthetized quantum dots(QDs) and facilitate the penetration of electrolyte. Meanwhile, in this specific configuration, the presence of anatase–rutile heterojunction at the interface could help the rutile TNAF layer to efficiently collect photo-injected electrons from the anatase THPF layer thus suppressing the recombination of electrons and holes in electrolyte. The results showed that the PCE of QDSSC based on the TNAF photoanode was about 1.4-fold higher(η = 3.05%, J_(sc)= 15.86 m A cm^(-2), V_(oc)= 0.602 V, FF = 0.319) than that of device based on pure THPF(η = 2.20%, J_(sc)= 13.82 m A cm^(-2), V_(oc)= 0.572 V, FF = 0.278).
基金supported by the National Natural Science Foundation of China (NFSC nos. 51732004 , 91433106 , 21703071 , 21805093)
文摘The modification of polysulfide electrolyte with additives has been demonstrated as an effective way to improve the photovoltaic performance of quantum dot-sensitized solar cells(QDSCs). Most of these additives can inhibit the charge recombination processes at photoanode/electrolyte interface and favor the improvement of V oc of cell devices. Herein, we showed that the incorporation of elemental selenium(Se) in polysulfide electrolyte to form polyselenosulfide species can notably improve the performance of QDSCs. Unlike previous reports, we present here an integrated investigation of the effects of polyselenosulfide species in polysulfide electrolyte on the photovoltaic performance of QDSCs from both of the photoanode and counter electrode(CE) aspects. Electrochemical impedance spectroscopy(IS) and opencircuit voltage-decay(OCVD) measurements demonstrated that the introduction of Se into polysulfide electrolyte can not only retard charge recombination at photoanode/electrolyte interface, but also reduce the charge transfer resistance at CE/electrolyte interface, resulting in the improvement of J sc and FF values. Consequently, the average efficiency of Zn-Cu-In-Se QDSCs was improved from 9.26% to 9.78% under AM 1.5 G full one sun illumination.
基金financial supports from the National Natural Science Foundation of China (21503202, 61604143 and 61774139)Yunnan Provincial Natural Science Foundation (Grant No. 2017FA024)
文摘To pursue electron-generation stability with no sacrifice of photovoltaic performance has been a persistent objective for all kinds of solar cells. Here, we demonstrate the experimental realization of this objective by quasi-solid-state quantum dot-sensitized solar cells from a series of conducting gel electrolytes composed of polyacrylamide（PAAm） matrix and conductive polymers [polyaniline（PANi）, polypyrrole（PPy） or polythiophene（PT）]. The reduction of Sx2- occurred in both interface and three dimensional framework of conducting gel electrolyte as a result of the electrical conduction of PANi, PPy and PT toward refluxed electrons from external circuit to Pt electrode. The resulting solar cells can yield the solarto-electrical conversion efficiency of 2.33%, 2.25% and 1.80% for PANi, PPy and PT based gel electrolytes,respectively. Those solar cells possessed much higher efficiency than that of 1.74% based on pure PAAm gel electrolyte owing to the enhanced kinetics for Sx2- ？ S2- conversion. More importantly, the stability of quasi-solid-state solar cell is significantly advanced, arising from the localization of liquid electrolyte into the three dimensional framework and therefore reduced leakage and volatilization.
