Integrated Photon Upconversion Solar Cell via Molecular Self-Assembled Bilayers

Abstract

Molecular photon upconversion, by way of triplet−triplet annihilation (TTA-UC), is an intriguing strategy to increase solar cell efficiencies beyond the Shockley−Queisser limit. Here we introduce self-assembled bilayers of acceptor and sensitizer molecules on high surface area electrodes as a means of generating an integrated TTA-UC dye-sensitized solar cell. Intensity dependence and IPCE measurements indicate that bilayer films effectively generate photocurrent by two different mechanisms: (1) direct excitation and electron injection from the acceptor molecule and (2) low-energy light absorption by the sensitizer molecule followed by TTA-UC and electron injection from the upconverted state. The power conversion efficiency from the upconverted photons is the highest yet reported for an integrated TTA-UC solar cell. Energy transfer and photocurrent generation efficiency of the bilayer device is also directly compared to the previously reported heterogeneous UC scheme.

Optimizing photon upconversion by decoupling excimer formation and triplet triplet annihilation

“…Triplet-triplet annihilation photon upconversion (TTA-UC) can help light harvesting materials to overcome their bandgap limitation and thus achieve higher solar energy conversion efficiencies beyond the Shockley-Queisser limit. [1][2][3][4][5][6][7] The mechanism has recently been successfully incorporated in solar cells, [8][9][10][11][12][13][14] photocatalysts, [15][16][17][18] optical devices, [19][20][21][22][23][24] and light imaging. [25][26][27][28][29][30][31] It requires two functional species, a sensitizer and an annihilator.…”

Metal–Organic Framework Thin Film-Based Dye Sensitized Solar Cells with Enhanced Photocurrent

“…The fabrication of triplet–triplet annihilation up-conversion (TTA-UC) solar cell device is one of the ongoing interests to overcome the energy loss with suitable energy conversion materials [ 1 , 2 , 3 ]. The TTA-UC based solar cell devices can overcome the Shockley−Queisser limitations, enhance the efficiency and most importantly decrease the cost [ 4 ].…”

Recent advances in the application triplet–triplet annihilation-based photon upconversion systems to solar technologies

“…Notably, the power conversion efficiency from the upconverted photons is the highest yet reported for an SC integrated with sTTA-UC. 61 Further developing this strategy, to overcome the intrinsic limitation of porphyrin-like sensitizers, i.e., their narrow absorption bandwidth that limits the system absorptance, Dilbeck et al 62 recently introduced a trilayer architecture as a new system for incorporating multiple sensitizers into sTTA-UC film-based DSSC (Fig. 7).…”