Disheng Yao

The fabrication of high-performance submicrometer copper indium sulfoselenide (CISSe) absorbers from environmentally friendly solutions offers a promising strategy to reduce material consumption and enable large-scale production. However, the presence of a carbon residual layer in solution-processed absorbers typically limits device efficiency. To address this issue, this research employs a copper-indium-thiourea-N,N-dimethylformamide (Cu-In-TU-DMF) solution to fabricate high-quality CISSe (without a carbon residual layer). Furthermore, to mitigate nonradiative recombination loss, randomly distributed dielectric silica (SiO2) nanospheres (250 nm in diameter) are incorporated near the rear interface of the absorber. As a result, the proposed strategy simultaneously improves open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF), resulting in a champion device efficiency of 9.9%, with a Voc of 496.2 mV, a Jsc of 29.4 mA/cm2, and an FF of 67.6%. Moreover, when the SiO2 nanospheres are applied to passivate the rear interface of a semitransparent CISSe device fabricated on an indium tin oxide (ITO) back contact, all photovoltaic parameters are boosted. In summary, our research demonstrates that embedding SiO2 nanospheres into the absorber layer provides a simple and effective strategy for enhancing the performance of solution-processed solar cells. This method can be easily applied to other solution-based photovoltaic technologies, such as copper indium gallium selenide (Cu(In,Ga)Se2), copper zinc tin selenide (Cu2ZnSnSe4), antimony selenide (Sb2Se3), silver bismuth sulfide (AgBiS2), and perovskite solar cells.

In recent years, self-assembled molecular (SAM) hole-transport materials have boosted the efficiency of inverted perovskite solar cells. However, they also introduce numerous interfacial and structural challenges, presenting a double-edged sword for device development. Such as poor wettability for perovskite precursors-which adversely affects perovskite film quality-as well as insufficient stability and nonuniform formation. These issues cause localized inefficient charge transport and increased interfacial recombination, ultimately impairing device performance and reproducibility. To overcome these limitations, we introduced d-camphorsulfonic acid (D-CSA) as a multifunctional interfacial modifier. The strongly acidic sulfonic acid group (-SO₃H) of D-CSA plays a pivotal role: it enhances the wettability of the perovskite precursor on Me-4PACz ([4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid) and, acting as a proton donor, passivates the terminal carbazole group of Me-4PACz via protonation. Concurrently, the resulting sulfonate group (-SO₃^-) coordinates with undercoordinated Pb²⁺ ions from the perovskite layer. The incorporation of D-CSA also optimizes the energy level alignment between the HTL and the perovskite. The devices modified with D-CSA achieved a power conversion efficiency of 25.47% with negligible hysteresis, significantly outperforming the control devices (23.25%). Furthermore, the D-CSA-modified devices exhibited substantially enhanced moisture resistance, thermal stability, and operational stability under continuous illumination. This work provides a feasible strategy for developing highly efficient and stable inverted PSCs.

The performance of inverted p‐i‐n type perovskite solar cells (IPSCs) is limited by non‐radiative recombination caused by surface defects on the perovskite layer, which in turn leads to a loss of open‐circuit voltage ( V _OC ). In this study, a novel synergistic passivation strategy is proposed, which leverages the synergy between piperazine dihydriodide (PDI) and methylammonium iodide (MAI) to modify the perovskite/C ₆₀ interface in IPSCs effectively. This strategy fully utilizes the multiple structural and functional advantages of PDI. Its alkyl core‐electron cloud‐rich‐NH terminal can effectively coordinate with deep‐level defects, and the piperazine ring can interact with the FA ⁺ ions, inhibiting their migration. Furthermore, MAI, due to its small molecular size, can penetrate the perovskite surface and repair iodine vacancies ( V _I ). It also compensates for the deficiency of organic cations, achieving the ideal stoichiometric composition and enhancing interfacial contact. As a result, this synergistic strategy enhances energy level alignment, significantly suppresses non‐radiative recombination at the perovskite/C ₆₀ interface, and improves carrier transport efficiency. The optimized PSC based on this strategy achieves a high V _OC of 1.23 V (the theoretical limit for a 1.58 eV bandgap is 1.31 V, corresponding to a voltage deficit of only 0.08 V) and a PCE of 25.74%, and exhibits excellent long‐term operational stability.

Serious non‐radiative recombination at the interface hinders the improvement of power conversion efficiency (PCE) and stability in perovskite solar cells (PSCs). Meanwhile, the development of a comprehensive strategy for nontoxic and low‐cost additives to reduce surface defects in the perovskite absorber is a critical issue for the industrialization of PSCs. Herein, an organic compound extracted from Sugar orange peel (SPE), which simultaneously contains C═C bonds and methoxy groups, can act as a Lewis base to incorporate into perovskite for the passivation of undercoordinated Pb ²⁺ . To address the stability issue originating from iodide ion vacancies and organic cation vacancies, a synergistic passivation strategy by utilizing SPE and low‐toxicity piperazine dihydroiodide (PDI) was applied for the passivation at the perovskite/C ₆₀ interface. This strategy facilitates the in‐situ reconstruction of the perovskite film, yielding a homogeneous microstructure that minimizes the contact resistance at the perovskite/C ₆₀ interface. Furthermore, the synergistic effect of SPE and PDI markedly suppressed energy level mismatch‐induced and defect‐induced nonradiative recombination losses at the perovskite/C ₆₀ interface. Ultimately, the SPE&PDI‐treated PSC achieved a champion PCE of 25.4% and retained over 84% of its efficiency after being continuously annealed at 85°C for 1200 h.

This study investigates how molybdenum oxide (MoO_x) rear interface passivation—specifically its thickness and deposition conditions—affects CIGS thin-film solar cells. The MoO_x layer effectively suppresses selenium/sulfur diffusion into the molybdenum back contact during high-temperature processing, while improving the absorber’s microstructure by reducing interfacial voids. These modifications enhance electrical properties, yielding lower series resistance, higher shunt resistance, and improved fill factor and current density. Although recombination increases slightly, the reduction in voltage-related fill factor loss ultimately boosts hole extraction and suppresses electron recombination at the back contact. Consequently, MoO_x-passivated cells achieve superior performance, with industrial-scale modules (1650 mm × 658 mm) reaching 152.41 W output power and 14.0% efficiency. This work provides valuable insights for optimizing MoO_x-based interface engineering to improve CIGS solar cell efficiency and manufacturability.

Nickel oxide (NiO_x) is considered an ideal hole transport layer (HTL) in inverted perovskite solar cells (PSCs) due to its excellent carrier mobility and low cost. Electron-beam-evaporated NiO_x (E-beam-NiO_x) exhibits exceptional commercial potential due to its process compatibility. However, there are surface defects in E-beam-NiO_x, which are incompatible with perovskite (PVK) and limit its development. In this work, we used [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) as a self-assembled monolayer (SAM) and l-α-glycerylphosphorylcholine (GPC) to double modify the buried interface of E-beam-NiO_x films. SAM is used to modify interface defects of NiO_x, while GPC improves the wetting property and uniformity of the interface. Under the joint modification of SAM and GPC, the interface defects of NiO_x films were passivated, and the hole extraction ability of HTL was improved. At the same time, the growth quality of PVK films was improved, and the energy level matching between NiO_x and PVK was optimized. After optimization, the small-area (0.0575 cm²) PSCs achieved a champion power conversion efficiency (PCE) of 23.31%, providing an effective strategy and direction for the preparation of high-efficiency PSCs by E-beam-NiO_x.

This paper reports two copper-based organic-inorganic hybrid perovskite single crystals, (2A5MP)₂CuX₄ (X = Cl, Br), synthesized by a halogen-regulated method. Through comprehensive characterization (single-crystal XRD, powder XRD, FTIR, Raman spectroscopy, TGA, and UV-vis DRS), we elucidated crystal structures, intermolecular forces, functional groups, bond configurations, optical properties, and thermal stability. Both compounds crystallized in the monoclinic space group C2/c. (2A5MP)₂CuCl₄ has an optical band gap of 2.47 eV and is stable up to 172 °C, while (2A5MP)₂CuBr₄ has a band gap of 1.66 eV with a stability of up to 185 °C. When Br^- occupies the X site, (2A5MP)₂CuBr₄ exhibits an optical band gap (1.66 eV) close to the optimal value for solar cell absorbers. Furthermore, replacing Cl^- with Br^- enhances thermal stability by 13 °C. Therefore, (2A5MP)₂CuBr₄ demonstrates significant potential as a light-absorbing layer for solar cells.