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Bifacial photovoltaic (PV) modules can capture both front and rear incident light simultaneously, thereby enhancing their power output. Achieving uniformity in rear incident light is crucial for an efficient and a stable operation. In this study, we present a simple, yet effective textured rear reflector, designed to optimize the performance and stability of bifacial PV modules. The three-dimensional textured surface was created using an ethylene vinyl acetate sheet (EVA) through a hot-press method at 150 °C. Subsequently, the textured EVA surface was coated with solution-processed silver ink, increasing the reflectance of the textured reflector through a low-temperature process. The integration of the developed textured rear reflector into bifacial crystalline silicon (c-Si) PV modules resulted in an additional 6.9% improvement in power conversion efficiency compared to bifacial PV modules without a rear reflector, particularly when the rear reflector is close to the PV module. Furthermore, the textured rear reflector may mitigate current mismatch among cells by randomizing incident light and uniformly redistributing the reflected light to the PV cells. Consequently, the proposed textured reflector contributes to the enhanced performance and stability of bifacial PV modules. [ABSTRACT FROM AUTHOR]

The accurate detection and classification of faults in photovoltaic (PV) systems contribute to enhancing their performance. Bypass diode (BD) heating is a common issue afflicting field‐installed PV modules. Although different fault modes exist, they exhibit similar characteristics, which hinder their early detection and classification. Thus, a real‐time fault detection and classification method for heated BDs in PV modules using thermoelectric devices (TEs) is proposed. When PV modules experience partial shading (PS) or exhibit bypass diode faults (BDFs), the temperature of the BD rises. By attaching a TE to the BD, the heat generated due to the PS or BDF can be converted into electrical energy. Additionally, the cause of bypass heating can be classified in real time by analyzing the TE's power‐generation capacity, considering the inverter status and ambient conditions. For example, the power generated by the TE is in the ranges of 8.5–14.7 (PS) and 28–49.4 mW cm−2 (BDF) under operating conditions. Moreover, the power generated by the TE under the PS and BDF conditions is sufficiently high to drive a communication system, guaranteeing the reliability of the detection system. Therefore, the proposed bypass heating detection system can classify the fault modes of PV systems in real time without external power. [ABSTRACT FROM AUTHOR]

Colloidal Ag(In,Ga)S2 nanocrystals (AIGS NCs) with the band gap tunability by their size and composition within visible range have garnered surging interest. High absorption cross-section and narrow emission linewidth of AIGS NCs make them ideally suited to address the challenges of Cd-free NCs in wide-ranging photonic applications. However, AIGS NCs have shown relatively underwhelming photoluminescence quantum yield (PL QY) to date, primarily because coherent heteroepitaxy has not been realized. Here, we report the heteroepitaxy for AIGS-AgGaS2 (AIGS-AGS) core-shell NCs bearing near-unity PL QYs in almost full visible range (460 to 620 nm) and enhanced photochemical stability. Key to the successful growth of AIGS-AGS NCs is the use of the Ag-S-Ga(OA)2 complex, which complements the reactivities among cations for both homogeneous AIGS cores in various compositions and uniform AGS shell growth. The heteroepitaxy between AIGS and AGS results in the Type I heterojunction that effectively confines charge carriers within the emissive core without optically active interfacial defects. AIGS-AGS NCs show higher extinction coefficient and narrower spectral linewidth compared to state-of-the-art heavy metal-free NCs, prompting their immediate use in practicable applications including displays and luminescent solar concentrators (LSCs). Colloidal semiconductor core-shell nanocrystals are sought after for photonic applications. Here, the authors report coherent heteroepitaxial growth of Ag(In,Ga)S2 core-shell nanocrystals with near-unity photoluminescence quantum yield across almost the full visible range. [ABSTRACT FROM AUTHOR]

The electrical stability of perovskite solar cells (PSCs) will play an essential role in their commercialization because field‐installed PSCs frequently operate under non‐ideal voltages. Particularly, an instantaneous extremely high voltage (IEHVs) from electro‐static discharge will be applied to PSCs due to friction in roll‐to‐roll processes. In addition, lightning strikes and surges from grids are plausible sources of IEHVs to field‐installed PSCs. Hence, the effect of IEHVs on PSCs is systematically investigated and a robust device structure is suggested. An IEHV severely deteriorates PSCs by destroying their diode characteristics. Physical and chemical damage from IEHVs to the interface between the perovskite film and buffer layers causes increased recombination losses and series resistance. To reinforce the heterointerface, a well‐known surface defect passivation method is adopted, adding excessive PbI2 to perovskite films. The excessive PbI2, mainly located at the interface, successfully protects PSCs from IEHV. Moreover, inserting well‐established defect passivation layers, C60, and phenethylammonium iodide into the interface of a perovskite film improves the device's stability against IEHV. Therefore, interface defect passivation is viable for stable PSCs against abnormal electrical stress. It is believed that this study will provide fundamental insights for designing electrically reliable PSCs, which is crucial for grid‐connected, field‐installed energy generation sources. [ABSTRACT FROM AUTHOR]