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Spiro‐Linked Molecular Hole‐Transport Materials for Highly Efficient Inverted Perovskite Solar Cells
摘要： Spiro-linked compounds have been used as benchmark hole-transport materials (HTMs) for the construction of efficient normal architecture (n-i-p) perovskite solar cells (PSCs). However, the heavy reliance on the use of dopants not only complicates the device fabrication but imposes long-term stability concern of the devices. Herein, it is reported that solution-processed dopant-free spiro molecules can serve as superior HTMs to fabricate efficient inverted (p-i-n) PSCs. Rational choice of orthogonal solvent allows us to solution deposit uniform and pinhole-free perovskite films without compromising the hole-extraction capability of the spiro-based interface layers. To illustrate the generality of the strategy, three spiro-linked molecules are investigated side by side as HTMs in one-step solution-processed CH3NH3PbI3 PSCs. Due to the favored energy-level alignment and high hole mobility, solar cells based on the HTM of spiro-TTB yield a high efficiency of 18.38% with open-circuit voltages (VOC) up to 1.09 V. These results suggest that small molecular HTMs commonly developed for normal structure devices can be of great potential to fabricate cost-effective and highly efficient inverted PSCs.
关键词： inverted solar cells,energy-level alignments,spiro-linked compounds,perovskites
更新于2025-09-12 10:27:22
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High perovskite-to-manganese energy transfer efficiency in single-component white-emitting Mn-doped halide perovskite quantum dots
摘要： Taking advantages of negligible reabsorption and no phase separation, single-component white-emitting phosphors are believed as new promising color conversion materials for white light-emitting diodes. As a potential candidate, Mn-doped lead halide perovskites are studied intensively, but rare works can realize pure white emission with a single component due to the challenge for realizing sufficient energy transfer efficiency from perovskite to Mn at the desirable emission wavelengths. In this work, we reported the synthesis of single-component white light halide perovskite quantum dots (QDs) by doping Mn into the host of CsPb(Cl/Br)3@CsPb(Cl/Br)x core–amorphous shell (CAS). The small size of zero-dimensional core in CAS structure has a strong quantum confinement effect, which can enhance the energy transfer efficiency from halide perovskite to Mn impurity dramatically. Our result shows 19.3 times higher energy transfer efficiency for Mn-doped CAS than that of ordinary Mn-doped CsPb(Cl/Br)3 nanocubes. As a result, as-prepared Mn-doped CAS QDs give rise to a white light emission with Commission Internationale de l’Eclairage (CIE) color coordinates of (0.37, 0.33). After blending with polystyrene (PS), Mn-doped CAS QDs can be used as a single-component color conversion material for assembling white light LEDs.
关键词： energy transfer efficiency,white-emitting phosphors,white light LEDs,Mn-doped lead halide perovskites,quantum dots
更新于2025-09-12 10:27:22
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CdS Quantum Dots‐Organometallic Halide Perovskites Bilayer Electrodes Structures for Supercapacitor Applications
摘要： Supercapacitors are attracting great attention because of their fast charging?discharging ability as well as high power density. The current research in this area focuses mainly on exploring novel low-cost electrode materials with higher energy and power densities. In this work, thin film electrochemical capacitors were fabricated using layers of self-synthesized cadmium sulfide quantum dots and organometallic halide perovskite materials as active electrodes. Organometallic halide perovskites exhibit interesting ionic responses besides its extraordinary electronic property. These properties are exploited in fabricating the electrochemical capacitors, and the devices showed excellent cycling ability with stable capacitances output beyond 4000 cycles. Impedance spectroscopy measurements revealed that perovskites do not only serve as active electrodes but also as solid electrolytes thereby enhancing capacitance of the devices and hence energy densities. The layers provide high surface areas for electrolytes to access the electrode materials; reasonably low charge transfer resistance and small relaxation time were also observed. This work opens new opportunities for developing thin film supercapacitors using low-cost electrode materials and employing a facile, inexpensive solution process coating.
关键词： Perovskites,CdS,quantum dots,supercapacitor,bilayers
更新于2025-09-12 10:27:22
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First-Principles Screening of Lead-Free Mixed-Anion Perovskites for Photovoltaics
摘要： Organic-inorganic hybrid lead perovskites have made rapid progress in photovoltaic fields. However, the toxicity and poor long-term stability of these materials still limit their further commercial application. Herein, we proposed a system of lead-free mixed-anion perovskites in which a chalcogen element is incorporated into the perovskite octahedrons to improve the system stability. We performed first-principles calculations of the bandgaps of 192 lead-free mixed-anion perovskites belonging to the class of ABX'X"2, where A=Cs+, CH3NH3+, and HC(NH2)2+; B=Ga3+, In3+, Sb3+, Bi3+; X'= O2-, S2-, Se2-, and Te2-, and X"= F-, Cl-, Br-, and I-. The bandgap shows a linear relationship with the average anion electronegativity. The contribution of anions to the band edge states is related to electron affinity and structure parameters. Considering multiple factors forming perovskites, we screened out a promising candidate, CsInOBr2, with a suitable bandgap (1.3 eV) for application in photovoltaics.
关键词： theoretical screening,GLLB-SC methods,photovoltaic materials,lead-free perovskites,bandgap
更新于2025-09-12 10:27:22
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2D Nanoplates and Scaled-up Bulk Polycrystals of Ruddlesden-Popper, Cs2PbI2Cl2 for Optoelectronic Applications
摘要： Two-dimensional (2D) layered Ruddlesden-Popper (RP) phases of halide perovskite offer exotic properties and interesting structure, which make them suitable candidate for solar photovoltaics, light emitting diode (LED) and photodetector applications. Simple and scaled-up synthesis, chemical transformations, doping and stability are the important steps towards the applications. Herein, all-inorganic RP phase of Cs2PbI2Cl2 was synthesized via a facile hot-injection method using benzoyl halides as halide sources. Different morphologies in the form of 2D nanoplates (NPLs) and small nanocrystals (NCs) were obtained by changing the concentration of capping agents (i.e., oleic acid and oleylamine) in solution. The excitonic absorption peak was appeared for NPLs and NCs, which is the characteristic feature of 2D halide perovskites. Further, the scalable quantity (~1 gm) of bulk powder and micron-sized particles of Cs2PbI2Cl2 were synthesized via liquid assisted mechanochemical grinding and anti-solvent method, respectively. We have performed post-synthetic chemical transformation to synthesize three-dimensional (3D) CsPbBr3 disk-shaped particles and zero-dimensional (0D) Cs4PbCl6 NCs from the pre-synthesized RP Cs2PbI2Cl2 NCs in solution and studied their optical properties. Finally, doping of Mn2+ was carried out in Cs2PbI2Cl2 NCs, which demonstrated typical feature of Mn2+ dopant emission along with host emission properties. Low-temperature (77 K) photoluminescence (PL) spectra reveal red-shifted and line-width broadening emission along with longer PL lifetime for both undoped and Mn-doped NCs compared to room temperature PL. Further, the temperature-dependent PL spectra and thermogravimetric analysis (TGA) revealed excellent thermal stability of Cs2PbI2Cl2. This work offers an insight for exploration of synthesis process, post-synthetic chemical transformation and dopant insertion in all-inorganic 2D RP perovskites, which is important step forward for application. Demonstrations of various simple synthesis of both the nano and bulk phases, structural transformation and detailed optical properties of doped and undoped RP perovskite halide nanostructures unfold innovative opportunities for applicability in optoelectronics such as in solar cell and photodetectors.
关键词： Synthesis,2D Halide Perovskites,Post-synthetic Transformation,Optical Properties,Mn-doping,Thermal Stability,Ruddlesden-Popper Phase
更新于2025-09-12 10:27:22
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Accelerating the Screening of Perovskite Compositions for Photovoltaic Applications through High‐Throughput Inkjet Printing
摘要： The exploration and optimization of numerous mixed perovskite compositions are causing a strong demand for high-throughput synthesis. Nevertheless high-throughput fabrication of perovskite films with representative film properties, which can efficiently screen the perovskite compositions for photovoltaic applications, has rarely been explored. A high-throughput inkjet printing approach that can automatically fabricate perovskite films with various compositions with high reproducibility and high speed is developed. The automatic sequential printing of four precursors forms 25 mixed films in a fast and reproducible manner. The obtained bandgaps, photoluminescence (PL) peak positions, and PL lifetimes allow for the efficient screening of perovskite compositions for photovoltaic applications. To exemplify this concept, among 25 tested films, two compositions CH3NH3PbBr0.75I2.25 (MA) and (HC(NH2)2)0.75(CH3NH3)0.25PbBr0.75I2.25 (FA0.75MA0.25) with a long (237 ns) and short (49.0 ns) PL lifetime, respectively, are screened out for device investigations. As expected, the MA-based device exhibits a much higher efficiency (19.0%) than that (15.3%) of the FA0.75MA0.25 counterpart. This efficiency improvement is mainly ascribed to a smaller dark saturate current density, a lower level of energetic disorder, more efficient charge transfer and decreased charge recombination losses, which are consistent with the much longer PL lifetime in the database.
关键词： perovskites,photovoltaic applications,inkjet printing,high throughput fabrication
更新于2025-09-11 14:15:04
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Interface Engineering in Tin Perovskite Solar Cells
摘要： As a rising star of lead-free perovskite solar cells (PCSs), tin-based PSCs have drawn much attention and made promising progress during the past few years. Notably, interfaces in the tin-based PSCs device have great impacts on performance enhancements. In this Review, the authors first demonstrate why the interface is especially crucial for tin-based PSCs device. It is proposed that the engineering of i) interface between perovskite grains in the film and ii) interface within the PSCs device are of great significance on the improvement of device functionality and stability. Then, the up-to-date studies on interface engineering of tin-based PSCs are reviewed, including the following strategies: i) passivation of trap states; ii) modification of interfacial layers; iii) construction of 2D/3D structure. At last, a future perspective and remaining challenges in this field are given, aiming to provide a comprehensive understanding of interfaces in tin-based PSCs and give some new thoughts on interface engineering for efficient PSCs device.
关键词： 2D/3D structure,interfaces,Sn perovskites,lead-free,solar cells
更新于2025-09-11 14:15:04
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Self‐Assembly of Hybrid Oxidant POM@Cu‐BTC for Enhanced Efficiency and Long‐Term Stability of Perovskite Solar Cells
摘要： The controllable oxidation of spiro-OMeTAD and improving the stability of hole-transport materials (HTMs) layer are crucial for good performance and stability of perovskite solar cells (PSCs). Herein, we report an efficient hybrid framework material, (POM@MOF) [Cu2(BTC)4/3(H2O)2]6[H3PMo12O40]2 or POM@Cu-BTC, for the oxidation of spiro-OMeTAD with Li-TFSI and TBP. When POM@Cu-BTC is introduced to the HTM layer as a dopant, the PSCs achieve a superior fill factor of 0.80 and enhanced power conversion efficiency 21.44 %, as well as improved long-term stability in an ambient atmosphere without encapsulation. The enhanced performance is attributed to the oxidation activity of this POM anions and solid-state nanoparticles. Therefore, research presents a facile way by using hybrid porous materials to accelerate oxidation of spiro-OMeTAD, further improving the efficiency and stability of PSCs.
关键词： hole-transport materials,metal–organic frameworks (MOFs),polyoxometalates,perovskites,solar cells
更新于2025-09-11 14:15:04
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Hole‐Boosted Cu(Cr,M)O <sub/>2</sub> Nanocrystals for All‐Inorganic CsPbBr <sub/>3</sub> Perovskite Solar Cells
摘要： The all-inorganic CsPbBr3 perovskite solar cell (PSC) is a promising solution to balance the high efficiency and poor stability of state-of-the-art organic–inorganic PSCs. Setting inorganic hole-transporting layers at the perovskite/electrode interface decreases charge carrier recombination without sacrificing superiority in air. Now, M-substituted, p-type inorganic Cu(Cr,M)O2 (M = Ba2+, Ca2+, or Ni2+) nanocrystals with enhanced hole-transporting characteristics by increasing interstitial oxygen effectively extract holes from perovskite. The all-inorganic CsPbBr3 PSC with a device FTO/c-TiO2/m-TiO2/CsPbBr3/Cu(Cr,M)O2/ structure carbon achieves an efficiency up to 10.18 % and it increases to 10.79 % by doping Sm3+ ions into perovskite halide, which is much higher than 7.39 % for the hole-free device. The unencapsulated Cu(Cr,Ba)O2-based PSC presents a remarkable stability in air in either 80 % humidity over 60 days or 80 8C conditions over 40 days or light illumination for 7 days.
关键词： CsPbBr3,inorganic hole-transporting materials,all-inorganic perovskite solar cells,long-term stability,perovskites
更新于2025-09-11 14:15:04
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Hole-Boosted Cu(Cr,M)O <sub/>2</sub> Nanocrystals for All-Inorganic CsPbBr <sub/>3</sub> Perovskite Solar Cells
摘要： The all-inorganic CsPbBr3 perovskite solar cell (PSC) is a promising solution to balance the high efficiency and poor stability of state-of-the-art organic–inorganic PSCs. Setting inorganic hole-transporting layers at the perovskite/electrode interface decreases charge carrier recombination without sacrificing superiority in air. Now, M-substituted, p-type inorganic Cu(Cr,M)O2 (M = Ba2+, Ca2+, or Ni2+) nanocrystals with enhanced hole-transporting characteristics by increasing interstitial oxygen effectively extract holes from perovskite. The all-inorganic CsPbBr3 PSC with a device FTO/c-TiO2/m-TiO2/CsPbBr3/Cu(Cr,M)O2/carbon structure achieves an efficiency up to 10.18 % and it increases to 10.79 % by doping Sm3+ ions into perovskite halide, which is much higher than 7.39 % for the hole-free device. The unencapsulated Cu(Cr,Ba)O2-based PSC presents a remarkable stability in air in either 80 % humidity over 60 days or 80 8C conditions over 40 days or light illumination for 7 days.
关键词： CsPbBr3,inorganic hole-transporting materials,all-inorganic perovskite solar cells,long-term stability,perovskites
更新于2025-09-11 14:15:04