Perovskite solar cells (PSCs) have attained considerable attention owing to their high-power conversion efficiency (PCE) and low manufacturing costs. However, the inadequate stability and lead leakage issues of PSCs remain as critical challenges impeding their practical implementation. In this work, we adopt an in situ self-polymerization strategy, with three monomers (N-Methylol acrylamide (NMA), N-(2-Hydroxypropyl) methacrylamide (2-HPMA), and N-(4-Hydroxyphenyl) methacrylamide (4-HPhMA)) introduced into the perovskite film. NMA and 2-HPMA undergo self-polymerization during the thermal annealing of the perovskite films, forming internal encapsulation within the perovskite film. In addition, the hydrogen bonding and chelating interactions between the perovskite and the polymers effectively suppress the defect states and significantly enhance the quality of perovskite films. Thus, the efficiency of devices increases from 22.41% to 25.06% after 2-HPMA modification. Moreover, the internal encapsulation effect induced by 2-HPMA endows PSCs with better long-term stability and humidity resistance. The unencapsulated device can retain 88% of its original PCE after storage in ambient air for 1000 h, and 86% of its pristine PCE after aging for 100 h at 60%‒80% relative humidity (RH) conditions. Furthermore, the interaction between the polymers and lead can largely inhibit lead leakage from unencapsulated PSCs.

The all-inorganic lead-free vacancy-ordered perovskite offers a promising avenue toward nontoxic and stable optoelectronic materials. Herein, we present a first-principles study of the structural stability, optical absorption, electronic structure, and mechanical behavior of Cs₂BCl₆ compounds with B-site substitutions (B＝Ge, Sn, Pb, Cr, Mo, W, Ti, Zr, and Hf). The structural analysis shows that the Cs₂BCl₆ perovskite with face-centered cubes has a stable chemical environment, especially Cs₂HfCl₆, Cs₂WCl₆, and Cs₂PbCl₆. Hf⁴⁺ and W⁴⁺ with high-energy d-state external electron configurations can further lower the valence band maximum position of the Cs₂BCl₆ structures and thus increase the band gap, assisting in tuning the optical absorption and emission properties of these structures in the optoelectronic application. For the light absorption properties of Cs₂BCl₆ materials, the best light absorption properties have been concluded for Ti⁴⁺, Cr⁴⁺, and Pb⁴⁺-based perovskite in the visible range due to a suitable band gap. Therefore, the excellent optical absorption and electronic properties make these vacancy-ordered perovskites promising candidates for optoelectronic applications.

The lead contamination and long-term stability are the two important problems limiting the commercialization of organic–inorganic lead halide perovskites. In this study, through an innovative multi-scale simulation strategy based on the first-principle calculations coupling with drift-diffusion model and Monte Carlo method, a new discovery is shed on the vacancy-ordered double perovskite Cs₂TiI₆, a potential nontoxic and stable perovskite material for high-performance solar cell and α-particle detection. The excellent photon absorption character and ultrahigh carrier mobility (μ_n = 2.26×10⁴ cm²/Vs, μ_p = 7.38×10³ cm²/Vs) of Cs₂TiI₆ induce ultrahigh power conversion efficiency (PCE) for both single-junction solar cell (22.70%) and monolithic all-perovskite tandem solar cell (26.87%). Moreover, the outstanding device performance can be remained even in high energy charge particle detection (α-particle) with excellent charge collection efficiency (CCE = 99.2%) and mobility-lifetime product (μτ_h = 1×10^–3 cm²/V). Furthermore, to our surprise, the solar cell and α-particle detector based on Cs₂TiI₆ material are able to withstand ultrahigh fluence proton beam up to 10¹³ and 10¹⁵ p/cm² respectively, which strongly suggests that semiconductor devices based on Cs₂TiI₆ material are able to apply in the astrospace. The multi-scale simulation connecting from material to device reveals that Cs₂TiI₆ perovskite has the great potential for photovoltaic cells, α-particle detection and even their space application.

CsPbI₂Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability. However, open-circuit voltage (V_oc) loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device performance. Here, we proposed a bilayer electron transport layer ZnO(bottom)/SnO₂(top) to reduce the V_oc loss (E_loss) and promote device V_oc by ZnO insert layer thickness modulation, which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier recombination. In addition, guanidinium iodide top surface treatment is used to further reduce the trap density, stabilize the perovskite film and align the energy levels, which promotes the fill factor, short-circuit current density (J_sc), and stability of the device. As a result, the champion cell of double-side optimized CsPbI₂Br perovskite solar cells exhibits an extraordinary efficiency of 16.25% with the best V_oc as high as 1.27 V and excellent thermal and storage stability.