Perovskite single crystals have attracted tremendous attention owing to their excellent optoelectronic properties and stability compared to typical multicrystal structures. However, the growth of high‐quality perovskite single crystals (PSCs) generally relies on temperature gradients or the introduction of additives to promote crystal growth. In this study, a vacuum evaporation crystallization technique is developed that allows PSCs to be grown under extremely stable conditions at constant temperature and without requiring additives to promote crystal growth. The new method enables the growth of PSCs of unprecedented quality, that is, MAPbBr₃ single crystals that exhibit an ultranarrow full width at half maximum of 0.00701°, which surpasses that of all previously reported values. In addition, the MAPbBr₃ single crystals deliver exceptional optoelectronic performance, including a long carrier lifetime of 1006 ns, an ultralow trap‐state density of 3.67 × 10⁹ cm⁻³, and an ultrahigh carrier mobility of 185.86 cm² V⁻¹ s⁻¹. This method is applicable to various types of PSCs, including organic–inorganic hybrids, fully inorganic structures, and low‐dimensional structures.

The excitonic effect significantly influences the optoelectronic characteristics of halide perovskites. However, consensus on the temperature modulated exciton binding energy remains elusive, even for extensively studied materials like MAPbBr₃ perovskites. In this study, we utilized UV-vis absorption spectra and the Elliott model to extract the exciton binding energies of MAPbBr₃ in the range of 170–290 K. Elliott model fitted results reveal a linear increasing trend in bandgap and exciton binding energy for both cubic and tetragonal phases with temperature, with the tetragonal phase exhibiting a higher increasing rate. Additionally, we found that regardless of the temperature, the strongest absorption peaks are always dominated by the exciton absorption, and our fitted exciton absorption peak blue-shifts with the increase of temperature, accounting for the observed blue-shift of the strongest absorption peak for our fabricated MAPbBr₃ sample. However, with the increase of temperature, the weight of continuum state absorption increases significantly, which widens the absorption tails to the longer wavelength, leading to the red-shift of Tauc-plotted optical bandgaps. This is the first work considering the temperature-modulated excitonic properties of halide perovskites, which offers valuable insights into the behavior of MAPbBr₃ under varying temperature conditions. After a series of theoretical simulations on the temperature modulated electronic properties, including band structures, carrier effective masses, optical dielectric properties and Born effective charges, we provide rational interpretations for the experimentally observed temperature induced variation of the optical properties. These works are helpful to deepen our understanding of the temperature modulated optical properties of MAPbBr₃ perovskites.

In exploring the viability of perovskite solar cells (PSCs) for Mars missions, our study first delved into their temperature endurance in conditions mimicking the Martian climate, revealing remarkable thermal stability within the temperature range of 173–303 K. We then pioneered the examination of PSC resilience to electrostatic discharge (ESD), a critical factor given the frequent Martian dust activities. In a custom-built Martian simulation chamber, we discovered that ESD exposure dramatically reduced the power conversion efficiency of these devices by more than half (55.4%) in just 90 s. This groundbreaking research not only advances our understanding of the potential of PSCs for Mars exploration but also opens new avenues for optimizing solar technology in extreme environments.