Spiro-TTB (2,2',7,7'-Tetra(N,N-di-p-tolyl)amino-9,9-spirobifluorene, CAS 515834-67-0) is an electron-rich hole-transport layer (HTL) material used in OLEDs, organic photovoltaics (OPV) and perovskite solar cells. Its structure is built on a spirofluorene core carrying four ditolylamine groups at the 2 and 7 positions.
Structurally it is a close relative of Spiro-OMeTAD, but methyl groups take the place of the four methoxyl groups. This makes the molecule somewhat less electron-rich and lowers its HOMO level (5.25 eV), which can deliver a higher open-circuit voltage (VOC) and improved device performance.
This unsublimed grade has a purity above 98% by 1H NMR and is supplied as a light yellow powder or crystals. In p-doped form with F6-TCNNQ it has been used as the hole-transport layer in red and green phosphorescent OLEDs, with reported maximum EQE values of 19.5%, 19.7% and 39.6% depending on the device stack.
- Hole-transport layer in perovskite solar cells, where its deeper HOMO level can raise open-circuit voltage.
- Hole-transport layer material for organic photovoltaic (OPV) devices.
- p-doped hole-transport layer (with F6-TCNNQ) in red and green phosphorescent OLEDs.
- Research into charge-carrier transport in spiro-linked organic semiconductor films.
| Brand | Ossila |
|---|---|
| CAS number | 515834-67-0 |
| Molecular formula | C81H68N4 |
| Purity | Unsublimed > 98% (1H NMR) |
| Category | — |
| Pack sizes | 500 mg, 1 g, 5 g |
| Physical form | Light yellow powder/crystals |
| Storage | — |
- Product code: M2192B1
- Full name: 2,2',7,7'-Tetra(N,N-di-p-tolyl)amino-9,9-spirobifluorene
- Molecular weight: 1097.43 g/mol
- Absorption: λmax 384 nm in DCM
- Fluorescence: λmax 413 nm in DCM
- HOMO: 5.25 eV
- Glass transition temperature: Tg = 146 °C
- Classification: Spirofluorene derivative, Hole transport layer materials, Perovskite solar cells, Organic electronics
- Order code: M2192B1
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