- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Cathode Interface Engineering Approach for a Comprehensive Study of the Indoor Performance Enhancement in Organic Photovoltaic
摘要： Organic photovoltaic (OPV) has a prospective future as a reliable energy harvesting to drive low power consumption devices for indoor applications. In this article, the outdoor (1 sun) and indoor (LED 2700K) performance of PTB7-Th:PC70BM inverted OPV with three different solution-processed electron transport layers (ETL = PFN, TiOx, and ZnO) were compared. The morphology, optical, and electrical measurements indicate the strong dependency of the OPV performance with the illumination conditions. The sample with PFN-ETL that shows the highest outdoor performance with power conversion efficiency (PCE) of 10.55% and the best-reported fill factor (FF) of 75.00% among PTB7-Th:PC70BM-based OPV, surprisingly exhibits the lowest performance when illuminated under 250–2000 lux LED 2700K. Meanwhile, the lowest outdoor performance performed by ZnO with PCE of 10.03% displays the best indoor performance with the PCE of 13.94% under 1000 lux and a PCE of up to 16.49% under 1750 lux LED lamp, respectively. The changes in the FF values can be estimated by incorporating the parasitic resistance effect due to the type ETL used. Besides, using impedance spectroscopy, we observed that indoor performance agreed well with the trend of charge collection efficiency.
关键词： impedance spectroscopy,Organic photovoltaic,electron transport layers,PTB7-Th:PC70BM,indoor performance
更新于2025-09-23 15:21:01
-
[IEEE 2020 IEEE Latin America Electron Devices Conference (LAEDC) - San Jose, Costa Rica (2020.2.25-2020.2.28)] 2020 IEEE Latin America Electron Devices Conference (LAEDC) - Impact of the Hafnium Oxide as Hole Blocking Layer on the Performance of Organic Solar Cells
摘要： The effects of hafnium oxide (HfO2) as hole blocking layer (HBL) on the stability and degradation under air environment of inverted bulk heterojunction organic solar cells (iOSC), using as donor material thieno[3,4b]thiophene-alt-benzodithiophene (PTB7) and as acceptor material [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) are presented. The ultrathin films of HfO2 layers 0.9 nm of thick were deposited by thermal evaporation. The highest power conversion efficiency obtained (PCE) was of 8.33%. The current density-voltage characteristic (J-V) was modeled through the ideal-diode equivalent circuit model. For comparison, cells with poly [(9,9-bis (30- (N,N-dimethylamino) propyl) -2,7-fluorene) -alt-2,7- (9,9-dioctylfluorene)] (PFN) and Zinc Oxide (ZnO) as hole blocking layer were fabricated. The three groups of cells were exposed to air for 1000 h. The electrical parameters extracted from the current density–voltage characteristic (J–V) were analyzed. The PCE for cells manufactured with HfO2 as HBL remains around 30% after 1000 h under air environment, showing less degradation than iOSCs with ZnO.
关键词： electron transport layer,HfO2,PFN,PTB7:PC70BM solar cells,hafnium oxide,organic solar cells,ZnO,Degradation,OSC stability
更新于2025-09-23 15:19:57
-
Impact of intentional photo-oxidation of a donor polymer and PC <sub/>70</sub> BM on solar cell performance
摘要： Impact of intentional photo-oxidation of a donor polymer and PC70BM on solar cell performance. A short lifetime is the main factor hindering the wider implementation of low-cost organic photovoltaics through non-ideal encapsulation layers is a known cause of degradation for polymer/fullerene based solar cells. To better understand the origin of this performance degradation, we study the effect of intentional exposure of the photo-active layer to simulated sunlight (AM1.5) in air both on the solar cell performance and on the molecular semiconductor materials. Cathode-free thin films of a blend of the electron donor polymer poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1) and the electron acceptor fullerene derivative [6,6]-phenyl-C70-butyric acid methyl ester (PC70BM) were exposed to simulated sunlight in air. Fourier-transform infrared spectra demonstrate the formation of carbonyl photo-oxidation products in the blend films, as well as in the pristine polymer and fullerene films. Solar cells prepared with photo-oxidized active layers show increasingly degraded electrical performance (lower short circuit current, open circuit voltage and fill factor) with increasing exposure time. The increased diode ideality factor indicates that trap-assisted recombination hinders device operation after exposure. The external quantum efficiency decreases drastically with increasing exposure time over the whole photon energy range, while the UV-vis absorption spectra of the blend films only show a mild photo-induced bleaching. This demonstrates that not only the photo-induced degradation of the solar cell performance is not predominantly caused by the loss in light absorption, but charge transport and collection are also hampered. This is explained by the fact that photo-oxidation of PC70BM causes bonds in its conjugated cage to break, as evidenced by the decreased p* intensity in C1s-NEXAFS spectra of PC70BM films. This degradation of unoccupied states of PC70BM will hinder the transport of photo-generated electrons to the electrode. Surface photovoltage spectroscopy gives direct evidence for gap states at the surface of a PC70BM film, formed after 2 hours of exposure and resulting in upward band bending at the PC70BM/air surface. These observations indicate that the photo-oxidation of PC70BM is likely to be the main cause of the performance degradation observed when the photoactive layer of a TQ1:PC70BM solar cell is intentionally exposed to light in air.
关键词： polymer/fullerene solar cells,photo-oxidation,organic photovoltaics,PC70BM,degradation,trap-assisted recombination,charge transport,TQ1
更新于2025-09-19 17:13:59
-
Combined parametric optimization of P3HT: PC70BM films for efficient bulk-heterojunction solar cells
摘要： In this report, the effects of photoactive blend compositions, film thicknesses, and annealing conditions on the P3HT:PC70BM solar cells performance and reproducibility was investigated. The performance of prepared devices was described by examining their absorption spectra, current-voltage characteristics and external quantum efficiency (EQE). The thickness of active layer was achieved as 190 nm, 125 nm, and 90 nm, by maintaining the spin speed. Current density (Jsc) slightly increases from 6.39 to 7.15 mA/cm2 with increase in thickness from 90 to 125 nm; however, with further increase in film thickness (190 nm), the Jsc was reduced to 4.39 mA/cm2. To optimize the device performance, four different compositions of PC70BM (1:0.6, 1:0.8, 1:1, and 1:12) were investigated at the most favorable film thickness ~ 125 nm. The effect of different PC70BM compositions on photovoltaic performance was demonstrated by X-ray diffraction (XRD) and Raman measurements that illuminated modification in structural properties. Additionally, annealing condition led to achieve the good phase separation for efficient charge separation and transport within P3HT: PCBM film which further leads to increased efficiency (PCE ~ 3.31%). These effects deliver valued facts for the choices of PC70BM amount in P3HT:PC70BM system, and this efficient device optimization might be useful in other efficient photovoltaic systems for better performance through excellent reproducibility.
关键词： P3HT:PC70BM,Composition,Film thickness,Solar cells,Photoactive layer
更新于2025-09-12 10:27:22