P-13 HTM is a derivative of P-11. It is also a solution-processable organic small-molecule designed for n-i-p perovskite solar cells. Compared with P-11, P-13 features a higher HOMO level that is better matched to perovskite layers, enabling improved energy level alignment.
For p-i-n devices, the P-13 HTM (bottom contact) is only compatible with vacuum-deposited perovskite layers because it can be affected by the solvents used in subsequent processing.