Page - 179 - in Photovoltaic Materials and Electronic Devices

Table 1, there is a relatively high improvement of short circuit current (Is.c) with the effect of our synthesized nanoparticle coating compared to both quite stable open circuit voltage (Vo.c) and fill factor (F.F). Overall, the increase in the current, and consequently the power, could be explained due to the increase in the rate of photoelectrons,whetherthroughahighergenerationrateduetoopticalconversions and/or thebettermobilityduetoaconductivenanostructurecoating. 4    Figure  3.  Emission  spectrum  of  REDC  NPs  under  simultaneous  excitations  of  both  near‐UV    (430  nm)  and  IR  (780  nm)  excitations.  The  surface  profile  of  the  coated  cell  is  shown  in  Figure  4,  with  focus  on  the  region  between  the  electrode  and  the  coated  edge.  It  could  be  observed  that  the  mean  thickness  of  the  coating  is  around  20  nm  with  quite  a  non‐unif rm  distribution  of  the  coating,  as  shown  in  Figure  4b  rega di g  the  inte sity  imaging,  whic   may  be  due  to  the  spin  coating  technique  itself.  This  coating  technique  could  be  considered  as  a  trade‐off  between  surface  uniformity  and  simplicity.  However,  other  coating  techniques  may  lead  us  to  miss  the  conductivity  of  the  nanostructures  due  to  missing  oxygen  vacancies  with  the  conversion  of  Ce3+  to  Ce+4.    (a)   (b) Figure  4.  (a)  Surface  profile  of  coated  cell  at  the  edge  between  coating  and  the  electrode  and    (b)  the  profile  distribution  with  the  intensity  map.  Figure 4. (a) Surface profile of coated cell at the edge between coating and the electrodeand(b) theprofiledistributionwith the intensitymap. Table1. Comparisonbetweencoatedandun-coatedcells. Condition Vo.c Is.c F.F η% Uncoated 0.5155 0.1537 0.6301 15.1075 coated cell 0.5095 0.1718 0.6322 16.7452 179