Time：2024-09-30 11:08 View：375
Low charge transfer resistance and the promotion of electron/hole transport are crucial in perovskite solar cells because they directly affect the efficiency and stability of the cell. The following points can explain in detail how to improve the performance of perovskite solar cells by reducing the charge transfer resistance and facilitating electron/hole transport:
The properties of the hole transport layer (HTL) play a key role in the photoelectric performance of perovskite light-emitting devices because of their controlling ability in carrier injection and charge transport. For example, the use of PolyTPD materials with high HOMO levels can effectively match the valence band of perovskite, thus promoting the smooth transfer of holes.
The addition of additives such as 18-diiodooctane (DIO) in the hole transport layer can improve the morphology of the film, make it smoother and denser, thus speeding up the carrier transport and reducing the non-radiative recombination and interface recombination in the device. In addition, improving the hole transport capacity through doping and other methods also helps to improve the fill factor (FF).
In organic electroluminescent devices, the introduction of LiF as a hole blocking/exciton limiting layer can effectively block the uncompounded excess holes entering the composite luminescent region and lead to their accumulation. This accumulation can increase the electric field in the electron transport region, thus improving the efficiency of electron transport.
The planar heterojunction structure is conducive to the separation, transport and collection of electrons and holes in perovskite solar cells. This structure can provide separate transport channels for electrons and holes, thereby improving overall battery performance.
The HOMO level of the hole transport material should match the valence band of the perovskite to ensure effective hole injection and transport. For example, spirofluorene small molecule hole transport materials have attracted much attention due to their excellent photoelectric properties, and their HOMO level matches well with the valence band of perovskite, ensuring effective hole injection.
Hole transport materials also play a key role in the inhibition of carrier recombination. For example, spiro-OMeTAD has very good application potential as an organic small molecule hole transport material in perovskite solar cells, and despite its complex synthesis steps, its excellent charge transport properties make it a key material for efficient batteries.
By selecting suitable hole transport materials, optimizing interface engineering, applying hole blocking/exciton limiting layers, and ensuring energy level matching of materials, charge transfer resistance can be effectively reduced and electron/hole transport can be promoted, thereby improving the overall performance of perovskite solar cells.
