TY  - JOUR
A1  - Sandberg, Oskar J.
A1  - Kurpiers, Jona
A1  - Stolterfoht, Martin
A1  - Neher, Dieter
A1  - Meredith, Paul
A1  - Shoaee, Safa
A1  - Armin, Ardalan
T1  - On the question of the need for a built-in potential in Perovskite solar cells
JF  - Advanced materials interfaces
N2  - Perovskite semiconductors as the active materials in efficient solar cells exhibit free carrier diffusion lengths on the order of microns at low illumination fluxes and many hundreds of nanometers under 1 sun conditions. These lengthscales are significantly larger than typical junction thicknesses, and thus the carrier transport and charge collection should be expected to be diffusion controlled. A consensus along these lines is emerging in the field. However, the question as to whether the built-in potential plays any role is still of matter of some conjecture. This important question using phase-sensitive photocurrent measurements and theoretical device simulations based upon the drift-diffusion framework is addressed. In particular, the role of the built-in electric field and charge-selective transport layers in state-of-the-art p-i-n perovskite solar cells comparing experimental findings and simulation predictions is probed. It is found that while charge collection in the junction does not require a drift field per se, a built-in potential is still needed to avoid the formation of reverse electric fields inside the active layer, and to ensure efficient extraction through the charge transport layers.
KW  - built-in potential
KW  - charge collection
KW  - charge transport layers
KW  - perovskite solar cells
Y1  - 2020
U6  - https://doi.org/10.1002/admi.202000041
SN  - 2196-7350
VL  - 7
IS  - 10
PB  - Wiley
CY  - Hoboken
ER  -