Compositional grading of CZTSSe alloy using exponential and uniform grading laws in SCAPS-ID simulation

Role of contact work function, back surface field, and conduction band offset in Cu2ZnSnS4 solar cell

“…Also, a slight blue shift has been done to the electron affinity value for AZO compared to ZnO to implement a type-II band (clifftype) alignment [34]. The device is illuminated from window layer side with AM1.5 spectrum using relevant SCAPS option at temperature 300 K. The relevant material parameters used in simulation are listed in Table IV [32,[39][40][41]. The simulated current-voltage (J-V) curve in main panel of Fig.2 shows a Voc of 0.66 V, a Jsc of 19.85mA/cm 2 , a FF of 63.6% and an efficiency of 8.42%.…”

“…Table II provides a guideline for important design issue in p-n heterojunction [27][28] and summary of earlier efforts on thin film solar cell optimization [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. This includes optimization of (a) the ratio of band gap, carrier densities in the absorber and the buffer layers for reduced interfacial recombination [30], (b) back contact work function [31,32,35], (c) CBO and the band alignment at the junction [34], (d) band gap grading in Ev and Ec [33,36,39], (e) back surface field (BSF) [43][44][45]. A simulation of CZTS solar cell by SCAPS and optimization of back contact work function, acceptor concentration and thickness of CZTS layer was performed by Patel et.…”

Towards highly efficient thin-film solar cells with a graded-bandgap CZTSSe layer

“…The common techniques for tackling this problem in thin-film solar cells are light trapping using nanostructures in front of the illuminated face of the solar cell [20][21][22], nanostructured backreflectors [23], and back-surface passivation [24]; however, let us note here that enhanced light trapping does not necessarily translate into higher efficiency [25,26]. The issue of low V oc , and therefore low η, of the CZTSSe solar cell can be tackled by grading the bandgap E g of the CZTSSe absorber layer in the thickness direction [27][28][29][30][31][32][33][34]. Since E g is a function of ξ ∈ [0, 1], the parameter which quantifies the proportion of sulfur (S) relative to that of selenium (Se) in CZTSSe [6,35,36], the bandgap can be graded in the thickness direction by changing ξ dynamically during fabrication [27].…”

Formation of a phase pure kesterite CZTSe thin films using multisource hybrid physical vapour deposition

“…In general, CZTSe films are fabricated using conventional non-vacuum based methods such as ball milling, sol-gel, electro deposition, spray-pyrolysis and vacuum based techniques such as co-evaporation, sputtering, e-beam evaporation methods etc [14][15][16][17][18][19]. For solar cell applications the films fabricated by hydrazine-based solution process have achieved a maximum power conversion efficiency of 12.6% [20,21]. This method is still not in extensive use due to the toxic processing nature of hydrazine route which hinders its mass production [19].…”