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The conversion of low energy photons into high energy photons via triplet-triplet annihilation (TTA) photon upconversion (UC) has become a promising avenue for furthering a wide range of optoelectronic applications. Through the decades of research, many combinations of triplet sensitizer species and annihilator molecules have been investigated unlocking the entire visible spectrum upon proper pairings of sensitizer and annihilator identities. Here, we reflect upon the seminal works which lay the foundation for TTA-UC originating from solution-based methods and highlight the recent advances made within the solid state primarily focusing on perovskite-based triplet generation.
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This content will become publicly available on January 28, 2027
Activating Solid-State Triplet–Triplet Annihilation Upconversion via Bulky Annihilators
Triplet−triplet annihilation (TTA) upconversion (UC), a process converting two low-energy photons into one of higher energy, has numerous promising applications. Commonly, TTA-UC systems consist of a sensitizer, which absorbs low-energy radiation, and an annihilator, responsible for TTA and emission of high-energy radiation. Despite the fact that solid-state operation is essential for many of the most attractive applications of TTA-UC, most studies on annihilator properties have been performed in solution. Here, we develop a strategy to activate solid-state TTAUC in materials previously shown to undergo singlet fission such as diketopyrrolopyrroles (DPPs) and dipyrrolonaphthyridinediones (DPNDs). Furthermore, we demonstrate a general approach to progressively enhancing UC yields with bulky alkyl moieties. Our design motif, combined with optimization of TTA UC thin films, enables solid-state TTA-UC in these highly stable DPP and DPND derivatives, reaching UC quantum yields up to 1.5%. We demonstrate that careful molecular design of TTA-UC materials is a powerful strategy toward efficient solid-state UC and an important step toward the realization of the vast potential of TTA-UC across a multitude of applications.
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- Award ID(s):
- 2011924
- PAR ID:
- 10682344
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Journal of the American Chemical Society
- Volume:
- 148
- Issue:
- 3
- ISSN:
- 0002-7863
- Page Range / eLocation ID:
- 3811 to 3819
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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