- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Molecular Doping for Hole Transporting Materials in Hybrid Perovskite Solar Cells
摘要： Hybrid lead halide perovskites have been revolutionary in the photovoltaic research field, reaching efficiencies comparable with the most established photovoltaic technologies, although they have not yet reached their competitors’ stability. The search for a stable configuration requires the engineering of the charge extraction layers; in this work, molecular doping is used as an efficient method for small molecules and polymers employed as hole transport materials in a planar heterojunction configuration on compact-TiO2. We proved the viability of this approach, obtaining significantly increased performances and reduced hysteresis on compact titania-based devices. We investigated the photovoltaic performance correlated to the hole transport material structure. We have demonstrated that the molecular doping mechanism is more reliable than oxidative doping and have verified that molecular doping in polymeric hole transport materials leads to highly efficient perovskite solar cells, with long-term stability.
关键词： stability,perovskite solar cell,hysteresis,F4-TCNQ,molecular doping
更新于2025-09-16 10:30:52
-
Morphology control of perovskite in green antisolvent system for MAPbI3-based solar cells with over 20% efficiency
摘要： Solvent engineering has been considered a reliable process for the fabrication of pinhole-free and highly crystalline perovskite thin films. Recently, green solvents have received immense attention, as the toxic antisolvents used in the conventional fabrication process cause environmental and health hazards. In this regard, ethyl acetate (EA) is a promising environmentally friendly antisolvent. Here, we present the fabrication of perovskites with controlled morphologies by changing the composition of the perovskite and the volume of EA in ambient humidity. The incorporation of [HC(NH2)2]PbIBr2 into a CH3NH3PbI3 matrix results in a grain size up to ~1.5 μm. This induces a considerable reduction of trap density, leading to the suppression of charge recombination and, consequently, improvement in the photoluminescence characteristics. The resulting power conversion efficiencies (PCEs) of the optimized devices are 20.93% and 19.51% for active areas of 0.12 cm2 and 0.7 cm2, respectively. The reduced diffusion of moisture along grain boundaries improves device stability. Further, by virtue of the excellent humidity resistance of EA, the film morphologies obtained at high relative humidity (50%) are similar to those obtained under dry conditions, exhibiting an impressive PCE of 20.11%. We believe that our optimized fabrication process using EA can be extended to other green antisolvent systems.
关键词： Green antisolvent,Ethyl acetate,Grain size,Solvent and compositional engineering,Perovskite solar cell
更新于2025-09-16 10:30:52
-
Investigation of Well-Defined Pinholes in TiO2 Electron Selective Layers Used in Planar Heterojunction Perovskite Solar Cells
摘要： The recently introduced perovskite solar cell (PSC) technology is a promising candidate for providing low-cost energy for future demands. However, one major concern with the technology can be traced back to morphological defects in the electron selective layer (ESL), which deteriorates the solar cell performance. Pinholes in the ESL may lead to an increased surface recombination rate for holes, if the perovskite absorber layer is in contact with the fluorine-doped tin oxide (FTO) substrate via the pinholes. In this work, we used sol-gel-derived mesoporous TiO2 thin films prepared by block co-polymer templating in combination with dip coating as a model system for investigating the effect of ESL pinholes on the photovoltaic performance of planar heterojunction PSCs. We studied TiO2 films with different porosities and film thicknesses, and observed that the induced pinholes only had a minor impact on the device performance. This suggests that having narrow pinholes with a diameter of about 10 nm in the ESL is in fact not detrimental for the device performance and can even, to some extent improve their performance. A probable reason for this is that the narrow pores in the ordered structure do not allow the perovskite crystals to form interconnected pathways to the underlying FTO substrate. However, for ultrathin (~20 nm) porous layers, an incomplete ESL surface coverage of the FTO layer will further deteriorate the device performance.
关键词： electron selective layer,pinhole,perovskite solar cell,dip coating,evaporation-induced self-assembly,mesoporous TiO2
更新于2025-09-16 10:30:52
-
Yolk-shell SnO2@TiO2 nanospheres as electron transport layer in mesoscopic perovskite solar cell
摘要： SnO2 nanoparticles were synthesized and modified by TiO2 shell through sol–gel method. Band gap energy and photoluminescence properties of SnO2 nanoparticles and yolk-shell SnO2@TiO2 nanospheres were investigated by UV–Vis absorption spectra and photoluminescence (PL) spectroscopy. The nanoparticles were used as electron transport layers (ETLs) for fabrication of perovskite solar cells (PSCs) and PSC based on yolk-shell SnO2@TiO2 ETL showed higher photon conversion efficiency (PCE = 11.28%) and lower hysteresis index (37%) compared with the PSC made of SnO2 ETL (PCE = 8.55% and hysteresis index = 52%). The increase in the short-circuit current density (Jsc), open circuit voltage (Voc), and subsequently PCE for the PSC based on yolk-shell SnO2@TiO2 ETL is attributed to the smoothness and uniformity of perovskite film, improvement of surface defects at the ETL/perovskite interface, and suitable energy band alignment for effective injection of electron from perovskite to the conduction band of TiO2 as well as from TiO2 to the SnO2. Electrochemical impedance spectroscopy (EIS) was employed to determine the charge transport resistance at the ETL/perovskite interface and confirmed the results obtained by the characteristic curve of the current density–voltage. The stability test of the devices displayed that long-term stability of PSC made of yolk-shell SnO2@TiO2 ETL is almost the same as the SnO2 ETL-based PSC because of the high resistance of SnO2 against the moisture and oxygen in the environment.
关键词： Yolk-shell SnO2@TiO2 nanospheres,Long-term stability,Perovskite solar cell,Photon conversion efficiency,Electron transport layer
更新于2025-09-16 10:30:52
-
A Solution-Processed Spinel CuCo2O4 as an Effective Hole Transport Layer for Efficient Perovskite Solar Cells with Negligible Hysteresis
摘要： Optimal optoelectronic properties of interfacial layers in perovskite solar cells are essential for achieving high power conversion efficiency. We herein demonstrated a solution-processed spinel CuCo2O4 as a hole transport layer to use in high-performance perovskite solar cells. The solution-processed CuCo2O4 possessed high electrical conductivity, high optical transparency in UV-Vis-NIR, well-matched energy levels to perovskite and efficient hole transport capability to perovskite layer. The optoelectronic properties of CuCo2O4 was finely controlled by optimizing the annealing temperature, leading to 14.12% power conversion efficiency in planar perovskite solar cells. Another impressive advantage for CuCo2O4-based hole transport layer is a negligible hysteresis of the device at very low scan rate, that brought highly stable and reliable photovoltaic performance. All the results studied in this work suggest the bright future of solution-processed CuCo2O4 as a novel hole transport layer in perovskite solar cells with high efficiency and good stability.
关键词： CuCo2O4,Hysteresis,Efficiency,Hole transport layer,Perovskite solar cell
更新于2025-09-16 10:30:52
-
A study of perovskite solar cell with a Fe <sup>3+</sup> /Ga <sup>3+</sup> doped TiO <sub/>2</sub> layer
摘要： Perovskite has a structure of a large number of solar cells, which is very promising for the rapid commercialization of large-scale, low-cost solar cells. Perovskite solar cells (PSCs) have many advantages, such as their simple processing techniques and inexpensive raw materials. The conduction band of TiO2 used in many PSCs coincides well with that of the perovskite active layer. In addition, TiO2 has excellent stability and conductivity and can be obtained by various low-cost deposition methods. However, TiO2 traps electrons in oxygen vacancies and Ti lattice sites; this leads to recombination, which in turn reduces the efficiency of the device. In this study, we investigated the effects of Fe3+ ions on the efficiency of PSCs by doping them in a compact and mesoporous layer of TiO2. As a result, the perovskite solar cell using TiO2 doped with Fe3+ and Ga3+ shows an open-circuit voltage of 0.974 V, current density of 21.909 mA cm?2, 66.646% fill factor, and 14.21% efficiency. Fe3+ and Ga3+ have a smaller atomic radius than Ti4+ and thus, can replace Ti cations. Furthermore, the Fe3+ and Ga3+ doping of TiO2 is considered to be superior for the photoelectric performance of PSCs.
关键词： Fe3+/Ga3+ doping,efficiency,perovskite solar cell,TiO2
更新于2025-09-16 10:30:52
-
Selfa??Assembled Ionic Liquid for Highly Efficient Electron Transport Layer Free Perovskite Solar Cells
摘要： The electron-transport-layer (ETL) free perovskite solar cells (PSCs) are attractive because of fewer layers and hence lower cost, but the lower photovoltaic performance, as compared to the ETL-contained PSCs, largely restricts their practical applications. Herein, we design and synthesize hydroxylethyl functionalized imidazolium iodide, whose single crystal structure is determined, and propose self-assembled ionic liquid on the conductive substrate for ETL-free PSCs. It is found that the self-assembly of the ionic liquid on the conductive substrate can lower the work function of the conductive substrate, enhance the interfacial electron extraction, and meanwhile retard interfacial charge recombination. As a consequence, the power conversion efficiency is remarkably improved from 9.01% to 17.31% upon the self-assembly of ionic liquid on the conductive substrate. This finding provides a new way to achieve highly efficient ETL free PSCs.
关键词： electron transport layer free,perovskite solar cell,self-assembly,Ionic liquid,work function
更新于2025-09-16 10:30:52
-
2-Methylimidazole as an interlayer for the enhancement of the open-circuit voltage in perovskite solar cells
摘要： The loss of open-circuit voltage is a major obstacle for approaching the theoretical value of the power conversion efficiency in hybrid perovskite solar cells. In this study, a feasible and effective strategy for modifying the interface between the perovskite and the mesoporous TiO2 layer is proposed and implemented for the first time using 2-methylimidazole as a coating layer. As a result, the open-circuit voltage in the perovskite solar cells is significantly improved by 80 mV. The electronic impedance spectroscopy and photoluminescence spectroscopy results demonstrate that the modification of 2-methylimidazole as an interfacial insulating layer suppresses the electron transfer back from the anode electrode to the perovskite active layer, thereby inhibiting the recombination of the carriers at the interfaces, which results in an enhancement of the open-circuit voltage in the device. The cell modified with 2-methylimidazole shows increases in the open-circuit voltage from 1.05 to 1.13 V and in the power conversion efficiency from 17.48% to 19.45%. The optimal device with an area of 1 cm2 also exhibits an impressive efficiency of 16.38%.
关键词： 2-Methylimidazole,Open-circuit voltage,Efficiency,Interfacial modification,Perovskite solar cell
更新于2025-09-16 10:30:52
-
Solvent Engineering of a Dopant-Free Spiro-OMeTAD Hole-Transport Layer for cm-Scale Perovskite Solar Cells having High Efficiency and Thermal Stability
摘要： High efficiency and environmental stability are mandatory performance requirements for commercialization of perovskite solar cells (PSCs). Herein, efficient cm-scale PSCs with improved stability were achieved by incorporating an additive-free 2,2’,7,7’-tetrakis[N,N-di(p-methoxyphenyl)amino]-9,9’-spirobifluorene (spiro-OMeTAD) hole transporting material (HTM) through simply substituting the usual chlorobenzene solvent with pentachloroethane (PC). A stabilized power conversion efficiency of 16.1% under simulated AM 1.5G 1-sun illumination with an aperture of 1.00 cm2 was achieved for PSCs using an additive-free spiro-OMeTAD layer cast from PC. X-ray analysis suggested chlorine radicals from pentachloroethane transferred partially to spiro-OMeTAD and retain in the HTM film, resulting of conductivity improvement. Moreover, unencapsulated PSCs having cm-scale active area cast from PC retained >70% of their initial PCE after ageing at 80 °C for 500 h, in contrast with less than 20% retention for control devices. Morphological and X-ray analysis of the aged cells revealed that the perovskite and HTM layers remain almost unchanged in the cells with spiro-OMeTAD layer cast from PC whereas serious degradation occurred in the control cells. This study not only reveals the decomposition mechanism of PSCs in the presence of HTM-additives, but also opens up a broad range of organic semiconductors for radical doping.
关键词： stability,spiro-OMeTAD,perovskite solar cell,hole transporting materials,dopant-free,radical,pentachloroethane
更新于2025-09-16 10:30:52
-
Rapid fabrication of perovskite solar cells through intense pulse light annealing of SnO2 and triple cation perovskite thin films
摘要： Rapid evolution of perovskite solar cells (PSCs) performance and stability has inclined the research focus towards scalable bulk fabrication through high speed and cost-effective automated methods. For the first time, intense pulsed light (IPL) is utilized to rapidly fabricate efficient PSCs through swift annealing of both the SnO2 electron transport layer (ETL) and mixed triple cation perovskite thin films. The addition of di-iodomethane (CH2I2) alkyl-halide could enhance the PSC efficiency by retarding the crystallization and improving the surface morphology of the perovskite photoactive film through supplying iodine cleaved by ultraviolet energy during IPL process. The maximum efficiency and fill factor of the PSCs fabricated by IPL annealing were 12.56% and 78.3% for the rigid glass-FTO slides, and 7.6% and 64.75% for flexible PET-ITO substrates when processed in the ambient with relative humidity of 60%, respectively. The annealed materials were characterized through Scanning electron microscopy (SEM), UV-vis, photoluminescence (PL), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques. In addition, impedance spectroscopy (IS) and current-voltage measurements were conducted to study the functionality of fabricated cells. Our results delineated the feasibility of sequential step IPL annealing on rapid fabrication of efficient PSCs which is directly applicable for scalable roll-to-roll manufacturing.
关键词： Di-iodomethane,SnO2,Rapid thermal annealing,Intense pulse light,Perovskite solar cell
更新于2025-09-16 10:30:52