Vanadium Oxide Post-Treatment for Enhanced Photovoltage of Printable Perovskite Solar Cells

Abstract

Printable perovskite solar cells (PSCs) have attracted widespread attention due to the simple fabrication process and low-cost raw materials. However, because no hole transport material is used and the carbon layer possess a relatively low work function of only 4.8–5.0 eV, a significant potential loss exists in printable PSCs, resulting in a relatively low open-circuit voltage (V OC). We employed vanadium oxide (VO x ) to post-treat the interface of carbon/perovskite, and effectively enhanced the photovoltage and PCE of printable PSCs. VO x possesses a high work function of ∼5.39 eV, and thus can facilitate the charge transfer from perovskite to carbon due to a more favorable energy level alignment. The V OC of the devices can be enhanced from ∼892.73 to ∼922.86 mV, delivering an average PCE of 14.47% and a champion PCE of 15.77%. In addition, this post-treatment method can also suppress the hysteresis of printable PSCs. The hysteresis index was reduced from 0.025 to −0.001 with VO x treated cells. This VO x post-treatment method is simple, easy to operate and compatible with various perovskite absorbers in printable PSCs, providing a promising prospect for further applications.

Tailoring the Dimensionality of Hybrid Perovskites in Mesoporous Carbon Electrodes for Type‐II Band Alignment and Enhanced Performance of Printable Hole‐Conductor‐Free Perovskite Solar Cells

“…have been employed in the perovskites for reducing the defect density and improving the charge transportation, [ 18,20,21 ] and various strategies have been developed to increase the work function of the carbon electrodes. [ 22,23 ] These approaches have been proved effective for enhancing the photovoltage of triple‐mesoscopic PSCs. At the same time, it is found that suppressing the charge recombination at the perovskite/carbon interface plays a significant role for fabricating devices with high V OC and PCE.…”

Efficient and Stable Perovskite Solar Cells Based on Inorganic Hole Transport Materials

“…Vanadium oxide (VO 2 ) is also an n -type semiconductor with a deep conduction band energy level, making it an appropriate HTL [ 82 , 83 ]. VO x on top of the perovskite layer using a ZrO 2 scaffold resulted in a PCE of 15.8% [ 58 ]. VO x was applied by post-treatment of the perovskite/carbon interface to facilitate the charge transfer from the high work function of VO x while not sacrificing the conductivity of carbon.…”

Perovskite Solar Cells: A Porous Graphitic Carbon based Hole Transporter/Counter Electrode Material Extracted from an Invasive Plant Species Eichhornia Crassipes

“…Though the mixed halide perovskite resulted in achieving improved device efficiency, its poor stability and degradation phenomena under the ambient environment have been a tailback for the commercial development of long-term stability PSCs [60][61][62] . As to control the degradation of perovskite structure due to moisture, heat, light and ion migrations 63 , several remedial measures have been reported which can make the perovskite structure to withstand under ambient conditions 64 and some of them are like incorporation and post-treatment of perovskite material using inorganic compounds 65 , composition engineering using mixed anions and cations 66 and also by introducing carbon-based materials 60,64 . Hence in the present study, an attempt has been made to overcome the above-mentioned drawbacks by encapsulating the perovskite material using carbon-based materials which could be used as an interfacial layer sandwiched between the active absorber and as prepared graphitic carbon counter electrode.…”