Solar RRL最新文献

Despite extensive research on utilizing plasmonic hot carriers to advance photovoltaics and photocatalysts, achieving high hot-carrier flux remains challenging due to their rapid relaxation. Recent studies have shown that combining plasmonic metals with perovskites improves hot-electron flow, due to the slow hot-electron relaxation in perovskites. Additionally, perovskites offer the advantage of facile bandgap tuning through composition changes. Herein, the influence of tuning the perovskite bandgap on the lifetime and flow of hot electrons in a perovskite/plasmonic Au/TiO₂ nanodiode is explored. The findings reveal that perovskites with wider bandgaps exhibit improved hot-electron lifetime and flow, attributed to the modified hot-electron energy favoring a slower energy loss rate, as verified by ultrafast transient absorption spectroscopic analysis. It is believed that the results successfully demonstrate the integration of engineered hot-carrier physics into device functions, providing valuable guidance for the design of optimized hot-carrier-based devices in the future.

The need to increase transparency in existing passivating contacts for crystalline silicon solar cells has motivated the development of transparent contacts based on transition metal oxides (TMOs). Among hole-selective materials, molybdenum oxide (MoO_x) has achieved the greatest success so far. However, despite providing low contact resistivity, MoO_x relies on an intrinsic hydrogenated amorphous silicon (a-Si:H(i)) interlayer to achieve high levels of surface passivation and thus high open-circuit voltage at a device level, partially defeating the objective of improved transparency. Herein, we report unprecedented performance for a-Si:H-free MoO_x-based contacts by employing an alternative passivating interlayer based on a well-engineered chlorine-containing Al-alloyed titanium oxide/titanium dioxide (Al_yTiO_x/TiO₂ )stack. The resulting Al_yTiO_x/TiO₂/MoO_x stack achieved record levels of passivation, reaching J₀ values as low as 16 fA cm⁻², closer to values reported for a-Si:H-based contacts, while maintaining lower contact resistivity, well below 100 mΩ cm⁻². Additionally, the stack presents improved transparency compared to a-Si:H-based contacts, with gains in short-circuit current density of at least 0.8 mA cm⁻². The work pushes the performance of hole-selective passivating contacts based on TMOs to new levels, enabling a record efficiency of 22.53% for cells with fully transparent hole-selective passivating contacts. This work serves as an important stepping stone toward low-thermal-budget, simple manufacturing of high-efficiency solar cells.

Epitaxial lift-off (ELO) InGaP/GaAs/InGaAs inverted metamorphic triple-junction solar cells are encapsulated with a micro/nanostructured polydimethylsiloxane (PDMS) film. The microprism array (MPA) is realized on the PDMS film to redirect the light incident on the metal grid line to the active area. Subwavelength structures (SWSs) are also introduced onto the PDMS film to suppress the Fresnel optical reflection loss. Triangular and hemicylindrical shapes are considered for the MPA. The optical responses of the two MPAs are calculated by using ray-tracing methods. The triangular MPA performs better than the hemicylindrical MPA in terms of light-redirection efficiency. It is confirmed that 82.0% of the light incident on the metal grid can be harvested by the effect of the triangular MPA and the Fresnel optical reflection loss is reduced effectively by the SWSs. These effects contribute to photocurrent enhancement. The short-circuit current density and power conversion efficiency of the flexible ELO triple-junction solar cells integrated with the micro/nanostructured PDMS film improve by 7.0% and 7.1%, respectively, compared with those of the solar cells without the PDMS film. By using the flexible PDMS film for light management, the flexibility of the ELO solar cells is preserved.

Halide perovskites are promising as the light absorbers of solar cells with efficient solar power conversion. However, why the degradation of perovskite solar cells (PSCs), especially at high temperatures, happens has not been completely understood to date. Herein, it is shown that evaporation of 4-tert-butylpyridine (4-tBP) from the hole transport layer (HTL) of 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene (spiro-OMeTAD) is one of possible degradation mechanisms in PSCs at a high temperature of 85 °C. In fresh PSCs, the chemical doping of the spiro-OMeTAD HTL with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is not so efficient because of the formation of a LiTFSI:4-tBP complex in the HTL. When PSCs are placed at 85 °C, 4-tBP gradually evaporates from the HTL, resulting in the dissociation of the LiTFSI:4-tBP complex. This 4-tBP evaporation enhances the chemical doping of spiro-OMeTAD by LiTFSI and makes the hole transport level of the spiro-OMeTAD HTL deeper, thereby impeding hole extraction at the perovskite/spiro-OMeTAD/Au interfaces. Herein, the 4-tBP evaporation by covering PSCs with a fluoro-polymer CYTOP layer, significantly improving the high-temperature durability of PSCs, is suppressed. The basic understanding obtained in this study would help promote the spread of more thermally durable PSC products in the future.

The exceptional optoelectronic performance and cost-effectiveness of manufacturing have propelled organic–inorganic hybrid perovskite solar cells (PSCs) into the spotlight within the photovoltaic community. Currently, the single-junction PSCs have achieved a certified power conversion efficiency surpassing 26%, edging closer to the illustrious Shockley–Queisser theoretical limit. To further enhance device performance, researchers are currently directing their attention toward the integration of wide-bandgap (WBG) perovskites (Eg > 1.60 eV) as top subcells in conjunction with narrow-bandgap materials, such as perovskite, crystalline silicon, and copper indium gallium selenium, to construct multijunction tandem devices that maximize solar spectral utilization and minimize thermal losses. However, WBG perovskites encounter challenges associated with suboptimal crystal quality, high defect density, and severe phase separation, leading to significant voltage losses and inferior performance. In this regard, extensive research has been conducted, yielding significant findings. This review article summarizes the advancements in composition engineering, additive engineering, and interface engineering of WBG PSCs. Furthermore, the applications of WBG PSCs in various tandem solar cells and their development are discussed. Finally, future prospects for the development of WBG PSCs are outlined.

In the last few years, there have been notable developments in organic solar cells using both small molecule donor and acceptor. It has been noted that adding halogens to the end groups of small molecules could enhance the film structure and, consequently, the performance of the devices. In this study, three novel small molecule donors are created. The molecules include a vinyl-CPDT oligomer with three units, with end-caps made up of indanedione groups and containing four H, four Cl, and four F substituents. The purpose of the study is to investigate how the halogen substituent affects the photovoltaic characteristics of binary devices made with the non-fullerene acceptor (NFA) TOCR2 as the acceptor. Having the halogen in the device enhances its effectiveness, and FG5, which has 4-Cl substituents in the end groups, shows the highest efficiency among all devices with a PCE of 14.39%. Incredibly, the ternary device that is created in normal atmospheric conditions with chloro-substituted FG5 as the donor, TOCR2 as the acceptor, and the wide band gap NFA DICTF as the third element shows significantly improved efficiency, achieving PCE values of up to 16.35%.

As the photovoltaics industry approaches the terawatt (TW) manufacturing scale, the consumption of silver in screen-printed contacts must be significantly reduced for all cell architectures to avoid risks of depleting the global silver supply and substantial cost inflations. With alternative metallization techniques (e.g., plating) facing their own challenges for mass production, advancements in the mainstream screen-printing technology to accelerate the pace of silver reductions are urgently needed. This work presents a silver-lean screen-printed contact scheme, providing scope for substantial reductions in silver consumption based on existing industrial screen-printing capabilities. The initial testing of such a design leads to the fabrication of 24.04% efficient large-area TOPCon solar cells with 9 mg W⁻¹ silver consumption compatible with existing soldering-based interconnection technologies, corresponding to a 25%_rel reduction in silver usage compared to standard industrial screen-printed TOPCon solar cells. Upon further optimization in pattern designs and fabrication processes, this silver-lean design offers a promising pathway toward ultra-low silver consumption of less than 2 mg W⁻¹ for screen-printed TOPCon solar cells without sacrificing efficiency.

Organic Field-Effect Transistors

Dual-acceptor-type multifunctional conjugated polymers based on diketopyrrolopyrrole-dioxo-benzodithiophene have been effectively employed as electron transport layer dopant in high-performance perovskite solar cells and as active channel semiconductor for ambipolar organic field-effect transistors. More in article number 2400185, Chu-Chen Chueh, Tsuyoshi Michinobu, Prashant Sonar, and co-workers.

Flexible Perovskite Solar Cells

In article number 2400243, Seong-Keun Cho, Dong Seok Ham, and co-workers suggest a transparent electrode-integrated flexible barrier substrate as an encapsulation material for protecting perovskite solar cells (PSCs) from air and moisture penetration. The encapsulated PSCs preserved 90% of initial device performance under harsh conditions (60 °C and 90RH%) for over 400 h.