ZnSe quantum dots downshifting layer for perovskite solar cells

Abstract

a b s t r a c tTo date, the instability of organometal halide perovskite solar cells (PSCs) has become the focus issue that limits the development and long-term application of PSCs. Both the ultraviolet (UV) rays in sunlight and moisture in air can significantly accelerate the disintegration of the perovskite. Here, we introduced a ZnSe quantum dots layer as downshifting materials, which was spin-coated onto the backside of PSCs. This layer converted the UV rays into visible light to prevent the destruction of PSCs as well as increase the light harvesting of the perovskite layer. Under the UV irradiation in the moisture ambient (40%), the destruction speed of the unencapsulated perovskite films were also delayed evidently. In addition, the power conversion efficiency (PCE) of the PSCs was increased from 16.6% to 17.3% due to the increase of the visible light absorbance of the perovskite.

Bandgap-Tuned CuInS2/ZnS Core/Shell Quantum Dots for a Luminescent Downshifting Layer in a Crystalline Silicon Solar Module

“…Quantum dots (QDs), which are inorganic semiconductor nanocrystals, have a broad absorption band, a high PLQY, and absorption and PL properties that are controllable by varying their particle size; therefore, they have been suggested as promising candidates for LDS materials in solar cells. 29 Cheng et al prepared LDS films by embedding CdS QDs in silica at 2.62 wt % and improved the short circuit current density (J SC ) of a c-Si solar cell by 4.0% at most under AM1.5G irradiation at 100 mW cm −2 . 16 Lopez-Delgado et al spin-coated CdSe/ CdS core/shell QD dispersions on a single c-Si solar cell to fabricate an LDS layer.…”

Recent Advances in Colloidal Quantum Dots or Perovskite Quantum Dots as a Luminescent Downshifting Layer Embedded on Solar Cells

“…A suitable LDS material can absorb UV rays and transform them into visible light, preventing the degradation and increasing the light-harvesting of the perovskite layer. In 2017, Wang et al developed an PSC that incorporated a spin-coated LDS layer of ZnSe QDs on the backside of the cell ( Figure 22 ) [ 196 ]. The uniform size of the QDs was achieved using the HI method, which absorbed significant amounts of UV light and converted it into visible light.…”

“… Schematic of PSCs with LDS layer of QDs, along with its working mechanism [ 196 ]. Figure reproduced with permission from Elsevier.…”

Enhancing the Photovoltaic Performance of Solid-State Dye-Sensitized Solar Cells with Composite Materials and Luminescent Down-Shifting

“…They demonstrated improvement in power conversion efficiency (PCE) from 16.61% to 17.33% due to improved absorbance of perovskite in the visible range of the solar spectrum. 38 In this work, a composite of luminescent species of ZnSe QDs and Ag nanoparticles (NP) as plasmon enhancer is investigated for a solid-state dye-sensitized solar cell (ss-DSSC), which act as down-shifting material and converts the undesired UV photons into significant visible light. The optical process involves deposition of an LDS layer on the top of fabricated device as shown in Fig.…”

“…The ZnSe QDs were prepared using the procedure described by Wang et al 38 The Ag NPs were synthesized using the process followed by Chouhan. 39 Initially, the Ag NPs were mixed with ZnSe QDs and ultrasonicated for 25 min.…”