Integrated Photon Upconversion Dye-Sensitized Solar Cell by Co-adsorption with Derivative of Pt–Porphyrin and Anthracene on Mesoporous TiO₂

Abstract

Photon upconversion via triplet–triplet annihilation (TTA-UC) is a process that converts two lower-energy photons to a higher-energy photon, which is expected to increase the maximum solar cell efficiency beyond the Shockley–Queisser limit. To incorporate TTA-UC into a dye-sensitized solar cell (DSSC), we used a co-adsorption approach, in which both a TTA-UC donor with an alkyl carboxylic acid chain and a TTA-UC acceptor dye were adsorbed onto mesoporous TiO 2 . Incident photon-to-current conversion efficiency spectra and excitation intensity dependence indicated that a photocurrent was generated under irradiation at wavelengths above 490 nm by the TTA-UC mechanism. The power-conversion efficiency of the DSSC was increased to 0.72%, and the photocurrent contributed by TTA-UC was 0.036 mA cm –2 under 1 sun irradiation.

Application of Triplet–Triplet Annihilation Upconversion in Organic Optoelectronic Devices: Advances and Perspectives

“…In order to solve the triplet energy migration and sensitizer solubility issue, a co-adsorption approach was introduced (Figure 8b). [199] In this approach, the sensitizer and annihilator are co-adsorbed on the surface of electrode with close proximity, which improved the TET and TTA efficiency thanks to the short distance between upconversion chromophores. An FoM of 0.036 mA cm −2 sun −2 has been achieved in a TTA upconversion [193] Copyright 2016, American Chemical Society.…”

“…integrated DSSC by co-adsorbing Pt(II)−porphyrin dye and diphenylanthracene on mesoporous TiO 2 . [199] Nevertheless, this approach has the disadvantage of the relatively low light harvesting efficiency since the concentration of sensitizer on the electrode surface is limited.…”

Harnessing near-infrared lightviaS0to T1sensitizer excitation in a molecular photon upconversion solar cell

“…4 TTA-UC can be harnessed in a solar cell using either optically [5][6][7][8][9] or electronically coupled schemes. [10][11][12][13][14][15][16][17] The latter relies on incorporating sensitizer and annihilator molecules directly into the solar cell and has achieved photocurrent enhancements up to 0.315 mA cm À2 . 18 While a promising proof of concept, all electronically coupled TTA-UC solar cells to date absorb visible light (i.e., o700 nm).…”

Efficiency of Thermally Activated Delayed Fluorescence Sensitized Triplet Upconversion Doubled in Three‐Component System

“…[ 1–5 ] TTA‐UC has gained great attention because it can proceed efficiently at low threshold intensities of incident incoherent light at or below 100 mW cm −2 . [ 1,6,7 ] This phenomenon was first discovered in single molecules of anthracene and phenanthrene as early as 1962, [ 8 ] continued research has produced increasingly efficient TTA‐UC systems and revealed the ease of tuning optical properties in multicomponent systems. [ 9–11 ] The first step in two‐component triplet upconversion is photon absorption by a sensitizer (donor) molecule, resulting in the generation of a singlet excited state, S 1 ( Figure a).…”