Industrial commercialization of perovskite solar cells not only depends on sufficient device performance, but also requires complete elimination of hazardous solvents in the fabrication process to ...enable sustainable development of the technology. This work reports a new solvent system based on sulfolane, Formula: see text-butyrolactone (GBL), and acetic acid (AcOH) as a significantly greener alternative to common but more hazardous solvents. Interestingly, this solvent system not only resulted in densely-packed perovskite layer of bigger crystal size and better crystallinity, the grain boundaries were found to be more rigid and highly conductive to electrical current. The physical changes at the grain boundaries were due to the sulfolane-infused crystal interfaces, which were expected to facilitate better charge transfer and provide stronger barrier to moisture within the perovskite layer, yielding higher current density and longer performance of the device as a result. In fact, by using a mixed solvent system consisting of sulfolane, GBL, and AcOH in the volume ratio of 70.0:27.5:2.5, the device stability was better and the photovoltaic performance was statistically comparable with those prepared using DMSO-based solvent. Our report reflects unprecedented findings of enhanced electrical conductivity and rigidity of the perovskite layer simply by using an appropriate choice of the all-green solvent.
Organic solar cells (OSCs) fabricated with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films often have limited performance due to high sheet resistances since commercial ...PEDOT:PSS contains a high insulating PSS to conducting PEDOT ratio. To resolve this issue, zinc iodide (ZnI2) additive was utilized to modify PEDOT:PSS films, which was carried out by mixing ZnI2 with PEDOT:PSS solution. The mixture was deposited on a fluorine-doped tin oxide substrate to derive the modified PEDOT:PSS films for application as a hole-transporting layer in OSCs. This resulted in an enhanced power conversion efficiency for OSCs fabricated with modified PEDOT:PSS films. The enhancement was primarily due to the improved PEDOT:PSS/PCDTBT:PC70BM (polyN-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl2',1',3'-benzothiadiazole) - PCDTBT, 6,6-phenyl-C71-butyric acid methyl ester - PC70BM) interfaces, which facilitates enhanced hole collection performance and results in a high current density for OSC devices. Moreover, the ZnI2 plays a role in the depletion of insulating PSS from the film's surface. This behavior causes lower sheet resistance and results in an increased Jsc and Voc for OSC devices. Therefore, the improved interfacial contact and depletion of PSS are considered synergistic functions for OSC enhancement.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Combination of directional solidification and convective deposition techniques was demonstrated for preparation of organic thin-film solar cells with ...polyN-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole) (PCDTBT) and 6,6-phenyl C71 butyric acid methyl ester (PC71BM) as the active layer, and 1,3,5-trichlorobenzene (135-TCB) as the solidifying reagent. The nucleation density and directional solidification of PCDTBT:PC71BM films were controlled by the amount of 135-TCB and the coating direction of convective deposition. We found that hole mobility and power conversion efficiency (PCE) of PCDTBT:PC71BM based solar cells can be enhanced by the addition of 135-TCB into the PCDTBT:PC71BM layer. Through the optimization of photovoltaic performance, 30% improvement of PCE was attained when 20 mg mL−1 of 135-TCB was used for preparation of the cell as compared to the device without 135-TCB under the atmospheric conditions.
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Hierarchical porous activated carbon/fly ash/PEDOT:PSS composites (AC:FA) for a counter electrode (CE) were created using a doctor blade technique and applied in dye sensitized solar cells. ...Hierarchical porous activated carbon (AC) was produced using a potassium hydroxide (KOH) activation process from cantaloupe peels (Cucumis melo L. var. cantaloupensis). AC was introduced into fly ash at various mass ratios to enhance several physical and electrochemical characteristics. Compared to bare FA, the AC:FA electrode displayed a high electrocatalytic activity for the iodide/triiodide redox (I−/I3−) reaction. The test findings show that a higher proportion of AC has an impact on a CE's catalytic activity and charge transfer resistance. The power conversion efficiency (PCE) of the dye-sensitized solar cell (DSSC) attained 5.81 % using the AC:FA CE with AC in a mass ratio of FA in 3:1 (wt./wt.), which is very near the performance of manufactured DSSC's with a platinum (Pt)-based CE (5.91 %). The AC:FA CE stands out as a strong candidate to substitute for costly Pt CEs due to its enhanced electrochemical activity and charge transfer capabilities obtained with an inexpensive and simple production procedure.
With high efficacy for electron-photon conversion under low light, perovskite materials show great potential for indoor solar cell applications to power small electronics for internet of things ...(IoTs). To match the spectrum of an indoor LED light source, triple cation perovskite composition was varied to adjust band gap values via Cs and Br tuning. However, increased band gaps lead to morphology, phase instability, and defect issues. 10% Cs and 30% Br strike the right balance, leading to low-cost carbon-based devices with the highest power conversion efficiency (PCE) of 31.94% and good stability under low light cycles. With further improvement in device stack and size, functional solar cells with the ultralow hysteresis index (HI) of 0.1 and the highest PCE of 30.09% with an active area of 1 cm2 can be achieved. A module from connecting two such cells in series can simultaneously power humidity and temperature sensors under 1000 lux.
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•Triple cation perovskite with 10% Cs and 30% Br is fit for collecting indoor light•High Cs/Br leads to wrinkle morphology and poor interface between perovskite and HTL•Carbon-based solar cell with ultralow HI of 0.1 and PCE of 30.09% can be achieved•Connecting 2 devices (1 cm2 active area) in series can power IoTs under 1000 lux
Devices; Energy materials; Materials science
Lead chalcogenides colloidal quantum dot (PbS CQD) solar cells employing an ordered bulk heterojunction (OBHJ) structure allow sufficient utilization of solar energy and at the same time ensure ...efficient charge extractions. However, the interfacial deficiency was determined to be a significant limiting factor for the further improvement of efficiency. Herein, a finely interpenetrating OBHJ structure between zinc oxide nanowire (ZnO NW) arrays and PbS CQDs was achieved by simultaneously controlling the growth orientation of ZnO NWs and introducing convective assembly as the CQD deposition technique. The inherent directionality during the assembly process leads to dense packing and efficient infiltration of CQDs, forming a valid OBHJ structure. Additionally, a self-assembled monolayer was introduced to further improve the V oc deficit. As a result, a record PCE of 9.92% has been demonstrated for OBHJ structured CQD solar cells that are compatible with low-temperature and scalable manufacturing processes.
An understanding of the spectrum–property relationship of perovskite solar cells when illuminated by light‐emitting diodes that are used for indoor applications is necessary. Herein, it is aimed to ...explore the influences of correlated‐color temperatures on a MAPbI3‐based device under low‐light conditions. Given an irradiance of approximately 3 W m−2 (or ≈1000 lx), a maximum free carrier generation rate of 1.0 × 1021 m−3 s−1 was found. Additionally, power conversion efficiencies (PCEs) up to 31.97%, 30.36%, and 28.98% with maximum power outputs of 13.66, 13.02, and 16.09 μW could be reached at 3000, 4000, and 6500 K, respectively. Additional increases in the PCEs were observed when high‐energy blue light (in a range of 400–550 nm) was excluded during the current–voltage sweeps. In combination with the surface photovoltage measurements, intense blue light (under 6500 K) had a minimal influence on the photoinduced charge separation signals when compared to those caused by 3000 and 4000 K light. As a solar cell, the PCE reached as high as 34.52%, which corresponded to 73.08% of the thermodynamic limit of its bandgap at 3000 K.
Herein, the impacts of the correlated‐color temperatures (CCTs) of LEDs on a single‐cation perovskite material MAPbI3 are highlighted. Based on the irradiant spectrum, an emphasis is placed on the theoretical prediction of the free carrier generation rate and maximum current density as a function of the CCT.
Dual electron transport layers of TiO2 and TiO2 mixed with AgInS2 quantum dots (TiO2:AgInS2 QDs) were used for planar heterojunction perovskite solar cells (PSCs). The addition of AgInS2 into TiO2 ...induced a reduction of pinholes at the interspace of the grains of the TiO2. The PL intensity of the perovskite film deposited on TiO2/TiO2:AgInS2 QDs was quenched by the addition of AgInS2 QDs into TiO2. A rectification ratio (RR) of the planar PSCs was improved by using TiO2/TiO2:AgInS2 QDs as dual electron transport layers. As a result, fill factor (FF) and power conversion efficiency (PCE) of the device with TiO2/TiO2:AgInS2 QDs (1.6 mg mL−1) increased up to 0.77 and 17.5% as compared with FF (0.73) and PCE (16.3%) of the device with TiO2 single layer. The device with TiO2/TiO2:AgInS2 QDs as dual electron transport layers showed the improvement of the external quantum efficiency in the wavelength region from 300 nm to 750 nm as compared with that of the device with TiO2 single layer. This result is probably caused by the enhancement of light harvesting by AgInS2 QDs and the enhancement of the charge transfer from the perovskite layer to the dual electron transport layers. The long-term stability of the PSC with the dual electron transport layers was confirmed when 1.6 mg mL−1 of AgInS2 was added, followed by the encapsulation and improvement of the retained PCE (after storing the device in air for 15 days), from 11% to 34%, as observed. As has been indicated, the TiO2/TiO2:AgInS2 QDs as dual electron transport layers not only brought about improvement of photovoltaic performance but also enhanced its durability against photodegradation.
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•Dual electron transport layers of TiO2/TiO2:AgInS2 QDs for planar perovskite solar cells (PSCs) was investigated.•The PL intensity of the perovskite film deposited on TiO2/TiO2:AgInS2 QDs was quenched by the addition of AgInS2 QDs.•The enhancement a rectification ratio (RR) of the planar PSCs by using TiO2/TiO2:AgInS2 QDs was observed.•The improvement of the EQE in the wavelength region from 300 nm to 750 nm of the device with AgInS2 QDs was investigated.•The long-term stability of the PSCs with the dual electron transport layers was confirmed.
Binary additives of 1,8-diiodooctane (DIO) and 1,3,5-trichlorobenzene (135-TCB) were utilized for preparation of poly4,8-bis(5-(2-ethylhexyl) thiophen-2-yl)benzo1,2-b; ...4,5-b'dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3fluorothieno3,4-bthiophene-)-2-carboxylate-2-6-diyl) (PTB7-Th) and 6,6-phenyl C71 butyric acid methyl ester (PC71BM) films for bulk heterojunction (BHJ) solar cells. The addition of binary additives of DIO 3.0 vol% + 135-TCB 2.1 vol% into PTB7-Th:PC71BM films exhibited nano-sized of PTB7-Th networks homogeneous distribution and smaller sizes than the film without additive and with DIO 3.0 vol%. The out-of-plane orientation of PTB7-Th:PC71BM films were improved by addition of binary additives and 135-TCB. A rectification ratio of the BHJ solar cells were improved by using binary additives of DIO 3.0 vol% + 135-TCB 2.1 vol%. As a consequence, fill factor (FF) and power conversion efficiency (PCE) of the device with binary additives increased up to 0.69 and 7.4% as compared with FF (0.66) and PCE (6.9%) of the device with DIO 3.0 vol%. The external quantum efficiency the device with binary additives was enhanced in the region from 550 nm to 750 nm as compared with that of the device with DIO 3.0 vol%. This result was probably caused by the improvement of PTB7-Th orientation, and phase separation between the PTB7-Th and PC71BM.
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•Binary additives of DIO and 135-TCB were utilized for preparation of BHJ films by convective deposition method.•Phase separation between the PTB7-Th and PC71BM films was improved.•The out-of-plane orientation of PTB7-Th in the BHJ films was enhanced by the addition of binary additives.•The improvement of a rectification ratio of the BHJ solar cells was observed.•The photovoltaic parameters were improved by using binary additives.
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