Efficient Vacuum Deposited P-I-N Perovskite Solar Cells by Front Contact Optimization

Abstract

Hole transport layers (HTLs) are of fundamental importance in perovskite solar cells (PSCs), as they must ensure an efficient and selective hole extraction, and ohmic charge transfer to the corresponding electrodes. In p-in solar cells, the ITO/HTL is usually not ohmic, and an additional interlayer such as MoO 3 is usually placed in between the two materials by vacuum sublimation. In this work, we evaluated the properties of the MoO 3 /TaTm (TaTm is the HTL N4,N4,N4 ′′ ,N4 ′′-tetra([1,1 ′-biphenyl]-4-yl)-[1,1 ′ :4 ′ ,1 ′′-terphenyl]-4,4 ′′-diamine) hole extraction interface by selectively annealing either MoO 3 (prior to the deposition of TaTm) or the bilayer MoO 3 /TaTm (without pre-treatment on the MoO 3), at temperature ranging from 60 to 200 • C. We then used these p-contacts for the fabrication of a large batch of fully vacuum deposited PSCs, using methylammonium lead iodide as the active layer. We show that annealing the MoO 3 /TaTm bilayers at high temperature is crucial to obtain high rectification with low non-radiative recombination, due to an increase of the electrode work function and the formation of an ohmic interface with TaTm.

Fully Vacuum‐Processed Perovskite Solar Cells on Pyramidal Microtextures

“…The reference devices on planar substrate yield efficiencies up to 18.22% which is comparable to commercial substrates using the same HTLs. [40] Looking at the performance, we find an increase mainly in V oc (devices type B and C), which is in line with the aforementioned TrPL analysis, showing a higher TrPL lifetime for films B and C. A higher TrPL lifetime can be correlated to a higher perovskite bulk and/or interface quality, which, in turn, expresses in a larger PL quantum yield and thus larger potential for higher V oc . [41] However, the overall PCE was lower for device type C, due to lower J sc and FF.…”

Wafer-scale pulsed laser deposition of ITO for solar cells: reduced damage vs. interfacial resistance

“…The deposition of the perovskite and charge transport layers followed the same procedure described in our previous publications. 43,44 The ST-PSC substrates were later shipped to the University of Twente for rear transparent ITO electrode fabrication by PLD. For the ITO PLD deposition, the substrates were aligned to shadow masks to obtain the electrode layout indicated in Fig.…”

Perspective on Predominant Metal Oxide Charge Transporting Materials for High-Performance Perovskite Solar Cells

“…Intensive research works have exhibited different strategies to passivate the defects, which likely concentrate at material interfaces to suppress charge recombination and hysteresis effect (Shao and Loi, 2020). Meanwhile, the interface between the CTL and conductive electrode should also be optimized for forming of a good ohmic contact for PSCs (Babaei et al, 2020;Tseng et al, 2020).…”