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Cu <sub/>12</sub> Sb <sub/>4</sub> S <sub/>13</sub> Quantum Dots with Ligand Exchange as Hole Transport Materials in All-Inorganic Perovskite CsPbI <sub/>3</sub> Quantum Dot Solar Cells
摘要： Perovskite solar cells (PSCs) have developed rapidly in the past ten years. However, they are faced with huge challenge on stability improvement because of the volatile organic component in light absorption and hole transporting layer. Herein, we fabricate all inorganic PSCs with the structure of FTO/c-TiO2/m-TiO2/CsPbI3 quantum dots (QDs)/Cu12Sb4S13 QDs/Au to improve device stability. To enhance the photovoltaic performance of PSCs, the surface oleylamine ligands of Cu12Sb4S13 QDs with 3-mercaptopropionic acid are exchanged, as the enhanced electronic coupling and reduced bandgap are realized after the ligands exchange. Cu12Sb4S13 QDs based PSCs exhibit a PCE of 10.02%, approaching to the Spiro-MeOTAD based PSCs (12.14%). A high short-circuit current density of 18.28 mA*cm-2 is achieved because of the enhanced light absorption and excellent hole extraction ability of Cu12Sb4S13 QDs. Moreover, Cu12Sb4S13 QDs based PSCs exhibit the improved long-term stability and retain 94% of their initial PCE after stored in ambient air after 360 h.
关键词： ligands exchange,hole transporting materials,photovoltaic efficiency,stability,Cu12Sb4S13 quantum dot,perovskite quantum dot solar cells
更新于2025-09-19 17:13:59
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Efficiency improvement of GaAs Quantum Dot in GaAs1-xPx matrix for solar cell applications
摘要： In this paper, we present simulations and the optimization of electrical and optical properties of GaAs Quantum Dots (QD) in a GaAs1-xPx matrix. Our results showed that 25 GaAs/GaAs1-xPx QD layers provide a relative enhancement of 41.34 % and 75.40 % of the short-circuit current and efficiency, respectively. With the same number of the QD layers, the External Quantum Efficiency (EQE) measurement shows that the absorption range edge of low energy photons has been extended from 875 to 1200 nm (?EQE= 25%). The temperature effect has been studied for a different number of QD inserted. The optimal conversion efficiency of 25 QD layers is degraded from 23.50% to 18.70 % by increasing the temperature from 273 K to 350 K. Moreover, the electrical features obtained and EQE measurements for GaAs/GaAs1-xPx QDSC have been compared with those obtained for In0.47Ga0.53As/GaAs0.86P0.14 QDSC, In0.167Ga0.53As/GaAs and GaAs reference cell, in order to show the better structure.
关键词： Quantum dot,solar cells,temperature effect,EQE
更新于2025-09-19 17:13:59
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Passivation via atomic layer deposition Al2O3 for the performance enhancement of quantum dot photovoltaics
摘要： PbS colloidal quantum dot solar cells (CQDSCs) are promising photovoltaic devices with a broad spectral response, solution processability and long-term air stability. Recently, major progresses have been achieved in the performance enhancement of CQDSCs through the chemical surface passivation of CQDs and the device engineering. However, the p-type PbS-EDT hole extraction layer presents high surface-trap density, which induces charge recombination risk and blocks the hole extraction at the PbS-EDT/Au interface. Herein, we demonstrated a method to passivate the surface traps of PbS-EDT film by post-depositing an aluminum oxide (Al2O3) layer using atomic layer deposition (ALD) technology. The ALD progress was carefully controlled to ensure that ALD Al2O3 could overcoat and infill the PbS-EDT film at the same time. This ALD Al2O3 treatment efficiently passivated the surface traps of PbS-EDT and successfully kept the proper band alignment at PbS-TBAI/PbS-EDT interface for the fast hole extraction of CQDSCs. Consequently, this method allowed the efficient carrier extraction at the PbS-EDT/Au interface through suppressing trap-induced reverse Schottky barrier. A power conversion efficiency of 7.07% was finally obtained in the PbS CQDSCs with ALD Al2O3.
关键词： PbS quantum dot solar cells,Atomic layer deposition Al2O3,Passivation,Traps
更新于2025-09-19 17:13:59
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ZnO@ZIF-8 inverse opal structure photoanode for efficient CdS/CdSe co-sensitized quantum dot solar cells
摘要： Photoanodes in quantum-dot-sensitized solar cells are essential to the process of light collection and charge transfer. In this paper, three-dimensional inverse opal (ZnO@ZIF-8 3D IO) photoanode is fabricated via a self-assembled opal template method. The synthesized photoanode has completely connected pores with extended diameter, thus promoting the permeability of QDs and electrolyte. Meanwhile, the light trapping ability and charge transfer process can be enhanced due to the slow photon and multi-scattering effect of the regularly interconnected macroporous array structure. ZIF-8 shell coated on the surface of ZnO IO not only provides high porosity but also serves as a protective passivation layer to reduce the carriers recombination occurred at the interfacial. In order to investigate the charge transport mechanism of ZnO @ ZIF-8 IO, cascaded CdS/CdSe quantum dots were used as sensitizers. Benefiting from the IO structure and ZIF-8 modification, the photoelectric conversion efficiency of solar cells based on ZnO@ZIF-8 IO can reach 1.75% (1.71 ± 0.04%), almost twice of that of the solar cells based on ZnO IO photoanode (0.81 ± 0.05%).
关键词： inverse opal structure,CdS/CdSe co-sensitized,ZnO@ZIF-8,photoanode,quantum dot solar cells
更新于2025-09-19 17:13:59
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Pressure-enhanced electronic coupling of highly passivated quantum dot films to improve photovoltaic performance
摘要： PbS colloidal quantum dot solar cells (CQDSCs) have recently achieved remarkable performance enhancement due to the development of the phase-transfer ligand exchange (PTLE) method. However, the lack of compact packing of the PTLE-passivated CQDs impairs the interdot electronic coupling and thereby severely restricts further improvement in performance. To address this electronic coupling issue, we report a simple yet effective process of external pressure (0–2 MPa). We ?nd that the interdot distance is reduced after the application of the pressure. Both optical and electrical measurements clearly demonstrate that the distance reduction can effectively strengthen the interdot electronic coupling, thus promoting the carrier transport of the CQD layer. However, too much pressure (>2 MPa) could accelerate the detrimental carrier recombination processes of CQDSCs. Accordingly, by optimizing the carrier transport and recombination processes, we achieve the maximum power conversion ef?ciency of 8.2% with a moderate pressure of 1.5 MPa, which is 25.5% higher than the solar cell without the external pressure. This effective strategy of external pressure could also be applied to other CQD-based optoelectronic devices to realize a better device performance.
关键词： external pressure,PbS colloidal quantum dot solar cells,phase-transfer ligand exchange,quantum dot films,Pressure-enhanced electronic coupling,photovoltaic performance
更新于2025-09-12 10:27:22
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High performance solid state solar cells incorporating CdS quantum dots and CH3NH3PbI3 perovskite
摘要： Since 2012, halide perovskites CH3NH3PbX3 (X = Cl, Br, or I) have been the topic of intensive research due to their excellent structural, optical and electronic properties and their application to perovskite solar cells (PSCs). PSCs are a new type of third-generation photovoltaics presenting low cost, ease of construction and power conversion efficiencies (PCEs) exceeding 23%, challenging the Si-based devices. This work describes a novel solution processed PSC structure: FTO/TiO2(CL)/mp-TiO2/CdS/Perovskite/Spiro-MeOTAD/Ag, using co-sensitization of quantum dots (QDs) with perovskite materials. This new cell architecture improves the device performance and characteristics and gives us the opportunity to develop solid state QDs cells.
关键词： quantum dot solar cells,CdS,co-sensitization,perovskite solar cells
更新于2025-09-12 10:27:22
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Efficiency Limit of Colloidal Quantum Dot Solar Cells: Effect of Optical Interference on Active Layer Absorption
摘要： Recently, colloidal quantum dot (CQD) solar cells have drawn intense attention because of their accessibility in low-energy solar photons with a facile tunability in electrical properties and their promising feature to go beyond the classic Shockley?Queisser limit of solar cells. Currently, state-of-the-art performance lead sulfide CQD thin-film-based solar cells have a PCE of approximately 12% with large room for improvement. To overcome current limitations on efficiency enhancement in CQD thin-film solar cells, the active layer thickness must increase first by improving carrier transport and formation of band bending to improve collection of carriers. We must note, however, in this heterojunction architecture, estimated optimal active layer thickness has to be revisited considering the interference effect. Specifically, the large refractive index difference between the PbS CQD layer and the ZnO layers account for a significant Fresnel reflection and optical interference in PbS CQD solar cells. This interference effect on high-performing PbS CQD solar cells may not only reduce the effective light absorption but also lead to underestimating the optimal active layer thickness.
关键词： colloidal quantum dot solar cells,optical interference,efficiency limit,active layer absorption
更新于2025-09-12 10:27:22
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Suppressing Interfacial Dipoles to Minimize Open‐Circuit Voltage Loss in Quantum Dot Photovoltaics
摘要： Quantum-dot (QD) photovoltaics (PVs) offer promise as energy-conversion devices; however, their open-circuit-voltage (VOC) deficit is excessively large. Previous work has identified factors related to the QD active layer that contribute to VOC loss, including sub-bandgap trap states and polydispersity in QD films. This work focuses instead on layer interfaces, and reveals a critical source of VOC loss: electron leakage at the QD/hole-transport layer (HTL) interface. Although large-bandgap organic materials in HTL are potentially suited to minimizing leakage current, dipoles that form at an organic/metal interface impede control over optimal band alignments. To overcome the challenge, a bilayer HTL configuration, which consists of semiconducting alpha-sexithiophene (α-6T) and metallic poly(3,4-ethylenedioxythiphene) polystyrene sulfonate (PEDOT:PSS), is introduced. The introduction of the PEDOT:PSS layer between α-6T and Au electrode suppresses the formation of undesired interfacial dipoles and a Schottky barrier for holes, and the bilayer HTL provides a high electron barrier of 1.35 eV. Using bilayer HTLs enhances the VOC by 74 mV without compromising the JSC compared to conventional MoO3 control devices, leading to a best power conversion efficiency of 9.2% (>40% improvement relative to relevant controls). Wider applicability of the bilayer strategy is demonstrated by a similar structure based on shallow lowest-unoccupied-molecular-orbital (LUMO) levels.
关键词： band engineering,quantum dot solar cells,interfacial dipole,hole transport layers
更新于2025-09-11 14:15:04