Perovskite solar cells have been studied extensively in the area of perovskite solar cells because they have a comparatively free hysteresis. Through fabrication of a perovskite solar cell based on a vanadium oxide buffer, this study clarified the mechanism of electron and hole transport in the laminated layer upon irradiation with light. The power conversion efficiency (PCE) of the Vanadium (Ⅳ) oxide (VO2) sputtering process device was approximately 13% and with the spin-coating process was 8.5%. To investigate the physicochemical origin of such PCE differences depending on the process type, comprehensive band alignment and band structure analyses of the actual cell stacks were performed using X-ray photoelectron spectroscopy depth measurements. Accordingly, it was found that the inconsistent valence band offset between the perovskite absorption layer and V2O5 layer as a function of the VO2 process type caused a difference in the hole transport, resulting in the difference in the efficiency. 相似文献
By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact(IBC) silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters(doping concentration and thickness) is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si:H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density. 相似文献
The electron transport layer (ETL) plays an important role on the performance and stability of perovskite solar cells (PSCs). Developing double ETL is a promising strategy to take the advantages of different ETL materials and avoid their drawbacks. Here, an ultrathin SnO2 layer of ~ 5 nm deposited by atomic layer deposit (ALD) was used to construct a TiO2/SnO2 double ETL, improving the power conversion efficiency (PCE) from 18.02% to 21.13%. The ultrathin SnO2 layer enhances the electrical conductivity of the double layer ETLs and improves band alignment at the ETL/perovskite interface, promoting charge extraction and transfer. The ultrathin SnO2 layer also passivates the ETL/perovskite interface, suppressing nonradiative recombination. The double ETL achieves outstanding stability compared with PSCs with TiO2 only ETL. The PSCs with double ETL retains 85% of its initial PCE after 900 hours illumination. Our work demonstrates the prospects of using ultrathin metal oxide to construct double ETL for high-performance PSCs. 相似文献
InP solar cell is promising for space application due to its strong space radiation resistance and high power conversion efficient (PCE). Graphene/InP heterostructure solar cell is expected to have a higher PCE because strong near-infrared light can also be absorbed and converted additionally by graphene in this heterostructure. However, a low PCE was reported experimentally for Graphene/InP heterostructures. In this paper, electronic properties of graphene/InP heterostructures are calculated using density functional theory to understand the origin of the low PCE and propose possible improving ways. Our calculation results reveal that graphene contact with InP form a p-type Schottky heterostructure with a low Schottky barrier height (SBH). It is the low SBH that leads to the low PCE of graphene/InP heterostructure solar cells. A new heterostructure, graphene/insulating layer/InP solar cells, is proposed to raise SBH and PCE. Moreover, we also find that the opened bandgap of graphene and SBH in graphene/InP heterostructures can be tuned by exerting an electric field, which is useful for photodetector of graphene/InP heterostructures. 相似文献
We fabricated kesterite Cu2ZnSnSe4 (CZTSe) solar cells and studied device characteristics, where CZTSe absorbers were made by using two-step process. First, we deposited precursor CZTSe films with spin-coating or sputtering, and performed sulfurization and subsequent selenization. To complete the device, we applied In2S3 as a buffer layer. We obtained power conversion efficiency (PCE) of 4.18% with spin-coated CZTSe absorber and 5.60% with sputtered CZTSe absorber. Both devices showed deep defects in the bulk and strong interface recombinations near the pn junction. In addition, we observed red-kinks in the current density-voltage (J-V) curves for both devices under the filtered light illumination (>660 nm), which is attributed to large conduction band offset (CBO) between the CZTSe absorber and the buffer layer and defect states in the buffer/CZTSe absorber or in the buffer. The red-kink was also observed in CZTSe (PCE of 7.76%) solar cell with CdS buffer. Hence, to enhance the PCE with CZTSe absorber, along with suppression of deep defects which act as recombination center, optimization of CBO between absorber and buffer is also required. 相似文献
CdSe nanocrystals are now known as highly efficient fluorescent light sources. Their efficiency is however strongly dependent on the quality of the passivation layers. We show here that using a ZnSe/ZnS bi-layer shell leads to a larger photoluminescence yield than both ZnSe and ZnS simple shells. The intermediate ZnSe layer acts as a lattice parameter adaptation layer to improve on the core/shell interface quality, while the ZnS outer shell maximizes the exciton confinement. 相似文献
Abstract—Two main factors which limit the power conversion efficiency of solar cells are light absorption and recombination processes. In photovoltaic (PV) devices, low energy photons cannot be absorbed and excite electrons from valance band to conduction band, hence do not contribute to the current. On the other hand, high energy photons cannot be efficiently used due to a poor match to the energy gap. Existence of charge recombination in PV devices causes the low conversion performance, which is indicated by the low open-circuit voltage (VOC). Using a blocking layer in system could effectively reduce the recombination of charge carriers. In this study, we simulated a solar cell with ITO/ZnO/P3HT&PCBM/Ag structure. To prevent the charge recombination, a ZnS QD layer was used which acts as a light absorbing and a recombination blocking layer in the ITO/ZnO film/ZnS QD/P3HT&PCBM/Ag structure. The simulated J–V characteristics of solar cells showed a close match with the experimental results. Simulate data showed an increase of conversion efficiency in ZnS QDSSC from 1.71 to 3.10%, which is relatively 81.28% increase. 相似文献
Antimony selenide is considering as an emerging photovoltaic solar cell absorber. In this paper, Solar Cell Capacitance Simulator in 1 Dimension (SCAPS-1D) is used to investigate the possibility of realizing ultrathin Sb2Se3-based solar cells. The comparison of the current-voltage characteristic and output performances simulation results of CdS/Sb2Se3 solar cells with and without HTL are in agreement with the experimental results. In the first step, by considering the cell without HTL, the best PCE of 5.29% is obtained with WS2 buffer layer. Thereafter, we simulated the impact of the charge carriers diffusion length and the doping concentration on the output performances. By combining a high quality absorber and doping concentration in the order of 1015 cm−3, Sb2Se3 solar cell achieves high PCE above 10%. Secondly, we introduced a HTL between the absorber layer and back metal contact, which led to n-i-p configuration. This configuration with CZ-TA HTL shows a best PCE of 6.29%. For a high quality absorber, Sb2Se3-based solar cell achieves best PCE of 11.10% and better stability for a thickness of 250 nm and doping concentration of 1014 cm−3 of the Sb2Se3 absorber layer. Our numerical solar cell design provides an approach to further improve the efficiency of Sb2Se3-based solar cells. 相似文献
Decreasing the absorber layer thickness of thin‐film solar cells can be an effective solution for cost reduction of photovoltaic electricity generation. Unfortunately, this reduction leads to detrimental effects such as incomplete photon absorption and increased charge carrier recombination at the rear electrode. To tackle these losses in ultra‐thin 0.5 µm Cu(In,Ga)Se2 (CIGS) solar cells, we developed different passivation structures made of MgF2 and Al2O3 at the molybdenum–CIGS interface, leading to localized back contacts. The influence of the distance between those contacts on the cell performance was studied by varying the periodicity of the applied 1D patterns from 6 μm to 30 μm. Thus, an increase in performance was measured for microstructured layers with a periodicity of up to 12 µm. More precisely, a MgF2 layer yielded an increase in power conversion efficiency (PCE) of up to 9%rel compared to an unpassivated cell design, and a passivation layer comprising Al2O3 led to up to a 5%rel increase in PCE. The gains were primarily attributed to an increased reflectivity of the back contact, while the formation of a negative backside field in the case of Al2O3 might have contributed to this increase by preventing electrons from recombining at the backside interface. Our findings indicate a high lateral conductivity for holes inside the multicrystalline CIGS compound over few tens of micrometres, which allows an independent design of future back contacts and light‐trapping schemes.
False‐colour scanning electron microscopy cross‐section picture of a passivated solar cell, with the front contact layers coloured in green, the 0.5 µm CIGS absorber in dark red, the MgF2 passivation layer in blue, and the Mo back contact in grey. 相似文献
Thin ZnSe layers were deposited on ZnO nanowires by a novel successive ionic layer adsorption and reaction technique in order to solve recombination problems in ZnO nanowire-based dye-sensitized solar cells (DSSCs). Cell efficiency increased from 0.1 to 1.3–1.4% with the deposition of a 9- to13-nm-thick ZnSe shell on ZnO nanowires due to a large increase in JSC. The dramatic increase in JSC and cell efficiency is due to the facilitation of electron transfer related to ambipolar diffusion by the formation of a type II band alignment and the suppression of recombination in the presence of the ZnSe shell. 相似文献
We fabricated Sb2 Se3 thin film solar cells using tris(8-hydroxy-quinolinato) aluminum(Alq3) as an electron transport layer by vacuum thermal evaporation.Another small organic molecule of N,N’-bis(naphthalen-1-yl)-N,N’-bis(phenyl)benzidine(NPB) was used as a hole transport layer.We took ITO/NPB/Sb2Se3/Alq3/Al as the device architecture.An open circuit voltage(Voc) of 0.37 V,a short circuit current density(Jsc... 相似文献
As the main distribution place of deep-level defects and the entrance of water, the interface is critical to determining both the power conversion efficiency (PCE) and the stability of perovskite solar cells (PSCs). Suitable interface design can dramatically passivate interface defects and optimize energy level alignment for suppressing the nonradiative recombination and effectively extracting the photogenerated carriers towards higher PCE. Meanwhile, a proper interface design can also block the interface diffusion of ions for high operational stability. Therefore, interface modification is of great significance to make the PSCs more efficient and stable. Upon optimized material choices, the three-dimensional halide perovskite graded junction layer, low-dimensional halide perovskite interface layer and organic salt passivation layer have been constructed on perovskite films for superior PSCs, yet a systematic review of them is missing. Thus, a guide and summary of recent advances in modulating the perovskite films interface is necessary for the further development of more efficient interface modification. 相似文献