Light-to-heat conversion represents one of the most promising pathways to utilize full-spectrum solar energy. The key for boosting the photothermal conversion in semiconductor-based light absorbers relies on narrowing the bandgap for harvesting wide-range sunlight and localizing thermal energy via decreasing heat loss. Here, we demonstrate the first example of using a halide perovskite, Cs4CuSb2Cl12, as the photothermal material for efficient solar-to-heat conversion, with an intrinsic narrow bandgap and ultralow thermal conductivity. Full-spectrum (200–2500 nm) absorption and solar-thermal conversion efficiency up to 93.4% are achieved. The photothermal property enables a low-temperature and rapid hydrogen production from ammonia borane, with 2.0 equiv of hydrogen released, and a photothermal activation efficiency of 12.2% is realized, without any extra energy input. This high photothermal performance not only provides a potential for an energy-efficient on-board hydrogen supply for fuel cells but also opens up a new field for halide perovskites utilized as photothermal convertors.
Colloidal lead halide perovskite nanocrystals (NCs) have recently emerged as versatile photonic sources. Their processing and optoelectronic applications are hampered by the loss of colloidal stability and structural integrity due to the facile desorption of surface capping molecules during isolation and purification. To address this issue, herein, we propose a new ligand capping strategy utilizing common and inexpensive long-chain zwitterionic molecules such as 3-(N,N-dimethyloctadecylammonio)propanesulfonate, resulting in much improved chemical durability. In particular, this class of ligands allows for the isolation of clean NCs with high photoluminescence quantum yields (PL QYs) of above 90% after four rounds of precipitation/redispersion along with much higher overall reaction yields of uniform and colloidal dispersible NCs. Densely packed films of these NCs exhibit high PL QY values and effective charge transport. Consequently, they exhibit photoconductivity and low thresholds for amplified spontaneous emission of 2 μJ cm–2 under femtosecond optical excitation and are suited for efficient light-emitting diodes.
The semiconducting bulk α-cubic CsPbI3 phase is stable at high temperature. However, recent developments concluded that in nanodimensions this phase can also be stable even at room temperature. The unique feature of these α-CsPbI3 nanocrystals is their low-energy red color emission, which remained an essential part for the perovskite family of nanocrystals to cover the entire visible spectrum. Even though these were reported to be stable at room temperature, it is only under certain conditions. These are mostly phase-sensitive, and under ambient conditions, the α phase is transformed to a nonemitting phase. Hence, the phase stability in these nanocrystals remained one of the major challenges in current research. In this Perspective, the origin of phase instability, observations of change in optical properties along with phase transformation under different environmental conditions, insights of possible modulations in A, B, and X sites of the perovskites, precaution in the purification process, and the ligand shell chemistry adopted during and postsynthesis for obtaining the stability of these CsPbI3 nanocrystals were systematically analyzed and reported. In addition, different possible aspects of future research for retaining the phase stability are also discussed.
In this work, we demonstrate the successful application of two-dimensional (2D) materials, i.e., graphene and functionalized MoS2, in perovskite solar cells (PSCs) by interface engineering the standard mesoscopic n–i–p structure. The use of 2D materials has the dual role to improve both the stability and the overall power conversion efficiency (PCE) of the PSCs compared to standard devices. The application of 2D materials is successfully extended to large-area perovskite solar modules (PSMs), achieving PCEs of 13.4% and 15.3% on active areas of 108 cm2 and 82 cm2, respectively. This performance results in record-high active area-indexed aperture PCE (AIAPCE) of 1266.5% cm2. In addition, the 2D materials-based PSMs show a stability under a prolonged (>1000 h) thermal stress test at 65 °C (ISOS-D2), representing a crucial advancement in the exploitation of perovskite photovoltaic technology.
Light-to-heat conversion represents one of the most promising pathways to utilize full-spectrum solar energy. The key for boosting the photothermal conversion in semiconductor-based light absorbers relies on narrowing the bandgap for harvesting wide-range sunlight and localizing thermal energy via decreasing heat loss. Here, we demonstrate the first example of using a halide perovskite, Cs4CuSb2Cl12, as the photothermal material for efficient solar-to-heat conversion, with an intrinsic narrow bandgap and ultralow thermal conductivity. Full-spectrum (200–2500 nm) absorption and solar-thermal conversion efficiency up to 93.4% are achieved. The photothermal property enables a low-temperature and rapid hydrogen production from ammonia borane, with 2.0 equiv of hydrogen released, and a photothermal activation efficiency of 12.2% is realized, without any extra energy input. This high photothermal performance not only provides a potential for an energy-efficient on-board hydrogen supply for fuel cells but also opens up a new field for halide perovskites utilized as photothermal convertors.
