Ultralow dark current in near-infrared perovskite photodiodes by reducing charge injection and interfacial charge generation

Riccardo Ollearo; Junke Wang; Matthew J Dyson; Christ H L Weijtens; Marco Fattori; Bas T van Gorkom; Albert J J M van Breemen; Stefan C J Meskers; René A J Janssen; Gerwin H Gelinck

doi:10.1038/s41467-021-27565-1

Ultralow dark current in near-infrared perovskite photodiodes by reducing charge injection and interfacial charge generation

Nat Commun. 2021 Dec 14;12(1):7277. doi: 10.1038/s41467-021-27565-1.

Authors

Affiliations

¹ Molecular Materials and Nanosystems, Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
² Integrated Circuits, Departments of Electrical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
³ TNO at Holst Centre, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands.
⁴ Molecular Materials and Nanosystems, Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands. r.a.j.janssen@tue.nl.
⁵ Dutch Institute for Fundamental Energy Research, De Zaale 20, 5612 AJ, Eindhoven, The Netherlands. r.a.j.janssen@tue.nl.
⁶ Molecular Materials and Nanosystems, Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands. gerwin.gelinck@tno.nl.
⁷ TNO at Holst Centre, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands. gerwin.gelinck@tno.nl.

Abstract

Metal halide perovskite photodiodes (PPDs) offer high responsivity and broad spectral sensitivity, making them attractive for low-cost visible and near-infrared sensing. A significant challenge in achieving high detectivity in PPDs is lowering the dark current density (J_D) and noise current (i_n). This is commonly accomplished using charge-blocking layers to reduce charge injection. By analyzing the temperature dependence of J_D for lead-tin based PPDs with different bandgaps and electron-blocking layers (EBL), we demonstrate that while EBLs eliminate electron injection, they facilitate undesired thermal charge generation at the EBL-perovskite interface. The interfacial energy offset between the EBL and the perovskite determines the magnitude and activation energy of J_D. By increasing this offset we realized a PPD with ultralow J_D and i_n of 5 × 10^-8 mA cm^-2 and 2 × 10^-14 A Hz^-1/2, respectively, and wavelength sensitivity up to 1050 nm, establishing a new design principle to maximize detectivity in perovskite photodiodes.