Progress in Photovoltaics最新文献

The European Commission's Photovoltaic Geographic Information System (PVGIS) uses a simplified solar energy yield model to provide quick and reliable data on the potential performance of photovoltaic (PV) systems. This study looks at the recalibration of the model for modern module technologies, using power matrix datasets produced by the European Solar test Installation (ESTI) for seven crystalline silicon (cSi), two cadmium telluride (CdTe) and three copper indium diselenide (CIS) modules. The results show that the PVGIS power performance model with updated coefficients can provide a good description of the power output of the modern crystalline silicon (cSi) modules, with a mean absolute bias error (MABE) of less than 1% in almost all cases, against an MABE of over 3.5% with the current coefficients. The updated coefficients allow the model to better capture the improved temperature coefficients and low light performance. As a result, there will be a slight increase in the energy yield estimates. For the thin film technologies, the updated coefficients allow for a more accurate description of current data sets, but more data for modules from recent production series would be desirable to further increase the model's applicability.

Monolithic perovskite/perovskite/silicon triple-junction solar cells have the potential to exceed the efficiency limits of perovskite/silicon dual-junction solar cells. However, the development of perovskite/perovskite/silicon triple-junction technology faces several significant hurdles, including the development and integration of a stable high bandgap perovskite absorber into the monolithic structure. Key issues include light-induced halide segregation in mixed halide high bandgap perovskites and the risk of solvent damage to underlying layers during top-cell deposition. To overcome these challenges, we developed a high bandgap, inorganic perovskite absorber, CsPbI₂Br, using thermal evaporation at room temperature, eliminating the need for post-deposition annealing. The resulting perovskite films exhibited a bandgap of 1.88 eV and demonstrated good photostability without any signs of halide segregation under continuous illumination probed over 3 h. Additionally, thermal evaporation offers a scalable approach for large-scale production, further enhancing the potential for widespread adoption of this technology. This advancement enabled the incorporation of CsPbI₂Br perovskite films into a monolithic perovskite/perovskite/silicon triple-junction device as the top-cell absorber. Consequently, we developed the first triple-junction device with an all-inorganic perovskite top-cell absorber using the thermal evaporation technique, achieving an efficiency of 21%, with an open-circuit voltage of 2.83 V over an active area of 1 cm². The device underwent 100 h of fixed voltage measurement near maximum power point under ambient conditions without encapsulation. Remarkably, it not only withstood the measurement but also exhibited an improved efficiency of ~22% afterwards, further demonstrating the stability and reliability of our thermally evaporated CsPbI₂Br perovskite absorber-based inorganic solar cell for monolithic triple-junction perovskite/perovskite/silicon applications.

Metastable behaviours with respect to light-soaking of Cu(In,Ga)Se₂ (CIGS) solar cells have long been known and studied, but no explanation has yet been fully agreed on. In this study, silver alloying and its impact on light-soaking effects is explored in four CIGS and six (Ag,Cu)(In,Ga)Se₂ (ACIGS) samples with high efficiency (17% to 21% before light-soaking). All were produced by co-evaporation and similar depositions protocols as the current world record device but with some variation. A variety of opto-electronic characterisation methods were used to explore the response to 24 h of light-soaking at 50°C. We found that (i) the open-circuit voltage increased for all ACIGS devices but decreased for the CIGS devices, (ii) the cells entered a state with higher doping and more tail states, and (iii) the effect was metastable and partially reverted after dark storage. While the improvement of the ACIGS cells saturates after 24 h in one-third of the irradiance at one sun, months are needed to reverse the open-circuit voltage change. Despite a higher doping after light-soaking, none of the samples' short-circuit current showed significant changes and the efficiency after light-soaking ranged from 15% to 22%. No long-range change in sodium or rubidium distributions was observed using glow-discharge optical emission spectroscopy. In general, external radiative efficiency measurements showed that the nonradiative recombination loss is reduced after light-soaking in the ACIGS devices. However, the correlation to the measured voltage was not always straight forward, presumably due to the graded bandgap of the absorber.

The tunnel oxide passivated contact (TOPCon) solar cell is predicted to dominate the photovoltaic market from the year 2024. The TOPCon efficiency is steadily increasing both in the lab and high-volume production. A notable new manufacturing technology, laser-assisted firing, has been shown to enhance the power conversion efficiency (PCE) of TOPCon solar cells. This enhanced contact firing technique includes a traditional co-firing step, followed by a laser scanning process in conjunction with an applied reverse bias. In this work, we utilize the Jolywood Special Injected Metallization (JSIM), a laser-assisted firing process developed by Jolywood that is already used in high-volume production. The performance of cells from the JSIM process was evaluated by comparing them to the cells fabricated using the baseline (BL) single-step firing process. The JSIM solar cells exhibited a notably higher PCE, approximately 0.58%_abs greater, compared with the BL cells. Detailed characterization demonstrated that the front (~280 fA/cm²) and rear (~98 fA/cm²) contact recombination of baseline (BL) cells are higher than those of JSIM cells (~88 fA/cm² and ~21 fA/cm², respectively), which is also the main advantages of the JSIM technology. Quokka 3 simulations were utilized to quantify the impact of the various improvements on the final solar cell performance. With the utilization of JSIM technology, contact recombination is no longer the primary source of power loss across the cell. Finally, the simulated results illustrated that the PCE of industrial JSIM cells could further be enhanced by ~0.3%_abs through optimizing the front screen pattern. This work clearly demonstrates the feasibility of laser-assisted firing in high-volume production, enabling significantly higher efficiency TOPCon solar cells by significantly reducing silicon-metal recombination. Consequently, laser-assisted firing increases the practical efficiency limit of TOPCon solar cells, bringing them close to levels that were previously only envisioned for heterojunction silicon solar cells.

External quantum efficiency (EQE) measurements of individual subcells in multijunction photovoltaic devices are essential to evaluate current matching and to iterate the design process. The standard light biasing technique used to measure subcell EQE falls short when multiple subcells absorb within the same spectral region. In this work, we demonstrate a three-step reverse voltage biasing EQE method, which measures any number of subcells with overlapping absorptance: (1) A light bias is applied to generate current mismatch between the subcells. (2) Current–voltage (I–V) characteristics are measured into reverse bias, where the limiting subcell enters reverse-bias breakdown and the device current climbs to a plateau at the photocurrent of the next limiting subcell, producing a staircase I–V curve. (3) Each subcell EQE curve is measured using a voltage bias within its current plateau. We demonstrate this approach for a two-junction GaAs-based photonic power converter, comparing to the standard light biasing method and revealing better than 0.8% absolute agreement when the top junction is preferentially biased in the reverse voltage biasing method. We demonstrate the viability of the method by measuring the EQE of all subcells in a six-junction GaAs-based photonic power converter.