Solar RRL最新文献

Following the impressive efficiencies achieved for two-terminal perovskite/silicon dual–junction solar cells, perovskite/perovskite/silicon triple-junction cells have now gained attention and are rapidly developing. In a two-terminal triple-junction cell, maximizing the open-circuit voltage (V_OC) is not straightforward as it requires understanding and mitigating the dominant losses in such a complex structure. Herein, the high bandgap perovskite top cell is first identified as the main source of the V_OC loss in the triple-junction cell. A multifaceted optimization approach is then implemented that improves the V_OC of the 1.83 eV perovskite. This approach consists of 1) replacing the reference triple-cation/double-halide with a triple-cation/triple-halide perovskite, which improves perovskite bulk quality and reduces transport losses, and 2) implementing a piperazinium iodide passivation between the perovskite and the electron transport layer, which reduces nonradiative recombination losses at this interface. Employing these optimizations in the top cell of the triple-junction boost the V_OC by average 124 mV. A high V_OC of more than 3.00 V is achieved with a fill factor of 79.6%, a short-circuit current density of 9.0 mA cm⁻², and an efficiency of 21.5%. Further study is conducted on the improvement of V_OC in the triple-junction solar cell using subcell selective photoluminescence-based implied V_OC imaging, which is applied for the first time to a perovskite-based triple-junction structure.

Perovskite-based solar cells have been extensively studied by the scientific community over the past decade and they are currently a very promising technology to be integrated into tandem perovskite module, for example, associated with silicon solar cells. However, one of the challenges lies in the upscaling of the production of perovskite solar cells from small laboratory-scale cells (<1 cm²) to larger modules. In this context, there is considerable interest in extending the analysis previously conducted on a micrometer or millimeter scale to a larger scale. In this work, for the first time, full-sample size hyperspectral absolutely calibrated photoluminescence (PL) imaging applied to 16 cm² perovskite semitransparent mini-modules is introduced. Herein, the inhomogeneities in PL emission observed between the different cells are investigated, highlighting shunt mechanisms and ion migration effects, as well as quantifying and evaluating the origins of the voltage losses. The impact of these inhomogeneities on device performance and stability is also addressed.

A modified chemical surface deposition (mCSD) method was introduced to confirm the advantages of buffer layers deposited heterogeneously using a solution process mechanism. In chemical bath deposition (CBD), an absorber is immersed in a mixed aqueous solution containing all cation and anion precursors; in chemical surface deposition (CSD), only the absorber surface participates in the reaction using mixed precursor solutions; and in mCSD, each cation and anion precursor reacts separately on the absorber surface, resulting in a heterogeneous reaction. Optimum conditions to form a buffer layer via a heterogeneous reaction in the mCSD process are determined by changing the deposition order of the precursor solution and solution combination. The CdS or Zn(S,O,OH) buffer layers formed under optimal mCSD conditions indicated higher photovoltaic performance in solar cells compared to that of the conventional CdS buffer layer formed by the CBD method. Temperature-dependent photovoltaic characteristics, capacitance–voltage measurements, and drive-level capacitance profiling were performed to investigate carrier transport behaviors, confirming that the solar cell with mCSD-CdS had less interface recombination. Further, the admittance spectroscopy for defect analysis indicated that a solar cell with the mCSD-processed buffer layer did not form deep defects compared to that with the CBD-processed buffer layer.

Photostable and efficient 1.8 eV wide-bandgap (WBG) perovskites are needed for all-perovskite tandem photovoltaic (PV) applications, but the high bromine (Br) content can cause halide segregation. To achieve the same bandgap with a lower Br content, MAPbCl₃ can be added to form triple-halide perovskites. However, most triple-halide WBG perovskites are still fabricated by antisolvent spin coating with perovskite inks that cannot be transferred to scalable deposition methods. Furthermore, the role of the Cl additives on the bandgap and the photostability remains elusive. Here, Cl-additives, such as ACl, PbCl₂, and APbCl₃ (where A denotes MA, FA, Cs, Rb), are systematically investigated to form 1.8 eV triple-halide perovskites with 30 mol% Br by N₂-assisted blade coating. It is found that PbCl₂ and APbCl₃ can increase the bandgap by several tens of meV, while ACl can only increase the bandgap by few meV. CsPbCl₃ emerges as a promising alternative to MAPbCl₃, enabling 17.2% efficient MA-free 1.8 eV triple-halide perovskite solar cells (0.062 cm²) with enhanced phase- and photostability. Its scalability is demonstrated by slot-die coating a ≈10% efficient WBG perovskite solar module with an aperture area of 52.8 cm².

Infrared light management is crucial to maximize the optical performance of crystalline Si-based single junction and tandem solar cells. For this end, a low refractive index dielectric is typically inserted under the rear metal and an electrical contact is obtained locally through the dielectric. However, the realization of such an architecture can require numerous fabrication steps that are time and resource intensive. Herein, a simple approach is proposed in which commercially available, low-cost SiO₂ nanoparticles (NPs) are spin coated as rear reflectors on pyramid-textured Si, leaving the pyramid tips locally exposed for direct contact by an electrode without additional patterning. In Si heterojunction solar cells, complementing a 40 nm-thick indium tin oxide (ITO) layer with the SiO₂-NPs yields a gain of 0.3 mA cm⁻² in short-circuit current density compared to that obtained with a bare, 100 nm-thick ITO layer. Combined with reduced electrical losses, power conversion efficiency gains of 0.5%_abs to 0.3%_abs for single junction Si and perovskite-Si tandem cells are demonstrated, respectively. Finally, it is shown that the NPs can also be processed on large areas via blade coating and that the process can be further simplified by a change in the fabrication sequence of the SiO₂-NP and ITO layers.

Transparent photovoltaic (TPV) devices represent a promising advance in photovoltaic technologies, particularly in building-integrated photovoltaics (BIPV). Unlike conventional photovoltaics, which primarily prioritize efficiency, TPV must balance between efficiency, transparency, and aesthetics. These additional dimensions introduce unique challenges on device architecture. This article reports the development of wide-bandgap, inorganic-based TPV devices integrating ultrathin hydrogenated amorphous silicon (a-Si:H) as a transparent absorber, with carrier selective contacts and transparent electrodes. The article analyzes how absorber thickness influences the electrical, optical, and aesthetic performance of devices, evaluating key parameters in TPV such as light utilization efficiency (LUE), average photopic transmittance (APT), color rendering index (CRI), and electrical properties such as power conversion efficiency (PCE). The device structure is SLG/FTO/AZO/a-SiC_x(n)/a-Si:H/V₂O_x/AZO. This approach results in PCE ranging from 1.7% with an APT of 60% to a PCE of 4.1% with an APT of 28%, yielding LUE values between 0.9% and 1.3%. Device characterization encompasses optical spectrophotometry, J–V measurements under standard test conditions, spectral response analysis, and variable illumination measurements (VIM). Additionally, color characterization is conducted using CIE 1931 color space maps to determine the chromaticity coordinates, CRI, and the variation of color as a function of absorber thickness.

Delicate regulation of halogens in conjugated molecules has emerged as a major strategy to modulate the aggregation of organic semiconductor materials for considerable enhancement of photovoltaic performance. Herein, three donor–π–donor hole-transporting materials, B₆P₆-F, B₆P₆-Cl, and B₆P₆-Br, containing 4,8-bis(hexyloxy)benzo[1,2-b:4,5-b′]dithiophene as a π-conjugated linker and 10-(6-fluorohexyl)-10H-phenoxazine, 10-(6-chlorohexyl)-10H-phenoxazine, and 10-(6-bromohexyl)-10H-phenoxazine respectively, as donor units, are reported. Differential scanning calorimetry curves, atomic force microscopy, and contact angle measurements with perovskite precursors collectively reveal that the halogenated alkyl chains attached to the donor units influence molecular packing patterns and subsequently alter the surface and interface properties of the resulting films. Analysis of Fourier-transform infrared absorption spectra implies that distinctive aggregation properties of B₆P₆-F may originate from its intermolecular F···π interactions. Benefiting from the F···π interactions and favorable self-assembly, the inverted PSCs based on B₆P₆-F exhibit a decent power conversion efficiency of 20.85%, outperforming that of B₆P₆-Cl and B₆P₆-Br. Further analysis of steady-state/transient photoluminescence spectra, electrochemical impedance spectroscopy, light intensity-dependent short-circuit photocurrent, and open-circuit voltage (V_oc) indicates that the distinct assembly of B₆P₆-F, facilitated by intermolecular F···π interactions, enhances efficient interfacial charge transport and extraction while suppressing unfavorable charge recombination, thereby increasing V_oc and fill factor.

Poor crystallinity is a common problem of kesterite absorbers based on non-hydrazine solution method, which obstructs charge transfer and affects photovoltaic performance of the thin-film devices, especially the open-circuit voltage (V_OC). Se diffusion is often insufficient during the crystal growth of kesterite absorber, resulting in uneven selenization reaction. Herein, Se molecule is introduced into kesterite precursor film to promote the absorber crystallinity while preventing the formation of a thick Mo(Se,S)₂ layer. It is found that after Se-introduction treatment, Se element distributes more uniformly in the absorber film after high-temperature annealing. During selenization, the lower part of the precursor film can easily obtain Se and experience crystallization, thus promoting the crystallization of the whole absorber. As a result, the absorber defects are passivated. According to charge carrier characterization, the carrier lifetime of the device is prolonged due to the reduced carrier recombination centers. Finally, a champion device with the V_OC increases by 23 mV, and an efficiency of 12.39% (active area efficiency of 13.57%) is achieved.

Aerosol jet printing (AJP) is an effective method for manufacturing organic photovoltaic (OPV) devices for indoor use. Its noncontact deposition, without posttreatment, and high-resolution 3D pattern printing capabilities make it ideal for using functional nanomaterial inks. This study explores ultrasonic AJP (uAJP) atomization to deposit silver nanowires (AgNW) as the top electrode layer (TEL) in OPV devices. The OPV stack is fabricated up to the hole transport layer using high-throughput screening (HTS) methodologies. Different deposition techniques, including spin-coating, blade-coating, and uAJP of AgNW inks, as well as thermal evaporation of silver, are compared. Scanning electron microscopy analysis shows that the E2X AgNW ink formed a compact TEL layer. Combining HTS setups, right selection of interlayers and uAJP method, automated, solution-processed OPV devices with power conversion efficiencies of 9.54% on an active layer of 0.0232 cm² are achieved, the highest reported for OPV devices using uAJP AgNW inks as top electrodes.