Solution-processed silicon/SnCl_(2)-treated Ti_(3)C_(2)T_(x) MXene Schottky junction solar cells

In this study,a novel photovoltaic cell based on the Ti_(3)C_(2)T_(x) MXene/n-type silicon(n-Si)Schottky junction is developed by a simple solution-processed method of drop-casting the Ti_(3)C_(2)T_(x) MXene ethanol suspension onto the surface of n-Si wafers and the subsequent natural drying in air.The demonstration device with a simple configuration of Ag(top electrode)/Ti_(3)C_(2)T_(x)/n-Si/In:Ga(back electrode)delivers a power conversion efficiency(PCE)of 5.70%with a short-circuit current density(Jsc)of 20.68 mA cm^(−2),open-circuit voltage(V_(oc))of 0.530 V and fill factor(FF)of 52.0%under AM 1.5G illumination.After treating the MXene layer with the SnCl_(2) aqueous solution,an improved PCE to 6.95%(J_(sc):23.04 mA cm^(−2);V_(oc):0.536 V;FF:56.2%)can be achieved because of the reduced light reflection,improved quality of junction and electrical contact,as well as the increased carrier lifetime/suppressed carrier recombination.Given the simple device configuration,facile preparation and huge potential for performance improvement,this work is believed to provide valuable exploration of developing novel solar cells.

Improved comprehensive performance of CsPbI_(2) Br perovskite solar cells by modifying the photoactive layers with carbon nanodots

Introducing additives into perovskite layers is an effective method to enhance the power conversion efficiency(PCE)and operation stability of perovskite solar cells(PSCs).Herein,we reported an addition of carbon nanodots(CNDs)into the CsPbI_(2) Br photoactive layer to boost performance of the related PSCs.It is found that the trap density can be notably suppressed,and the crystallinity can be enhanced after introducing CNDs with an optimal quantity.The PSC with 1.0 wt%addition of CNDs delivers a notable improved average PCE of 13.77%(the highest PCE:14.69%)from that of 12.14%for the control device without CND addition.Moreover,the CND-added CsPbI 2 Br PSCs exhibit superior stability,i.e.,~86% retention of the initial PCE after 160 h aging in air with the humidity of 20%-30%,to the control device.