Transparent and Colorless Dye‐Sensitized Solar Cells Based on Pyrrolopyrrole Cyanine Sensitizers

Abstract

The development of transparent solar cells extends the applications of photovoltaics by offering the opportunity to substitute the gigantic surface coverage of windows by solar panels to produce electricity. Herein, we report a new family of NIR-sensitizers based on pyrrolopyrrole cyanine dyes, particularly efficient for the development of fully transparent and colorless dyesensitized solar cells since a record efficiency of 2.5 % was achieved with an average visible transmittance (AVT) of 76 % and a color rending index (CRI) of 93.

First-principles study of electronic and optical properties in 1-dimensional oligomeric derivatives of telomestatin

“…The tunability of the oligomer's intrinsic electronic properties and combination of UV/IR absorption in the doped species suggests that the polyoxazoles could have important applications as optically transparent electronic materials in areas such as window-based photovoltaics. 77,78 The hole-doped species are of particular interest because of the longitudinal polarisation of their optical response in both the IR and UV regions.…”

Transparent Near‐IR Dye‐Sensitized Solar Cells: Ultrafast Spectroscopy Reveals the Effects of Driving Force and Dye Aggregation

“…As anticipated in the introduction, the thienyl units shift the absorption maximum by 30 nm into the red. The molar extinction coefficient is high (> 1.3×10 5 M À 1 cm À 1 ), due to πÀ π* transitions, [6] and almost the same for both dyes. The fluorescence spectra are Stokes-shifted by 45 nm for TB202 and 28 nm for TB207.…”

“…TB202 displays indeed a 30 nm-red shift of the absorption spectrum, and an improved AVT, but TB202's LUMO level is only slightly above the TiO 2 conduction band edge, resulting in a small driving force of À ΔG = 0.02 eV for electron injection, [7] as compared to 0.10 eV for TB207. [6] These values determined by electrochemistry (cyclic voltammetry) for the dyes in solution do not represent the real values in the TiO 2 devices. [19] Indeed, the electronic energy levels of the TiO 2 conduction band downshift due to the presence of 1 M Li + in the electrolyte by more than 100 m eV, [20][21][22] so that the nominal ΔG's become more negative for both dyes.…”

“…Since 45 % of sunlight radiation received on Earth lies in the near-IR (λ � 1700 nm), this part of the spectrum is presently targeted by the development of selectively near-IR absorbing solar cells (SCs), based either on organic photovoltaics (OPV) [1,4] or on DSSCs. [5][6][7] The transparency of the SCs is evaluated by the "average visible transmission" (AVT). For aesthetic reasons, the transparent see-through SCs should not alter the colors of transmitted images, which is quantitatively evaluated by the "color rendering index" (CRI).…”

A solid-state p–n tandem dye-sensitized solar cell

“…Conventional designs of ssDSCs feature a metal back contact, meaning incident light is obstructed from one side of the photoelectrode stack. The incorporation of transparent counter electrodes in ssDSCs offers a dual benet: it not only facilitates the penetration of incident light, a crucial aspect for various DSC applications like windows 27,28 or agrivoltaics, [29][30][31] but it also unlocks the potential for the fabrication of a tandem device. While semitransparent n-ssDSCs have been demonstrated, [32][33][34][35] a transparent back contact has not been realized in p-ssDSCs until now.…”