Toward quantum efficiency enhancement of kesterite nanostructured absorber: A prospective of carrier quantization effect

Abstract

In this work, the carrier confinement mechanism through nanostructures is studied in a copper-zinc-tin-sulfide/Cu2ZnSnSe4-type kesterite material, resulting in a remarkable performance enhancement of solar cells. The effect of the quantized energy band, recombination rate, and escape mechanism on the spectral response of solar cells is explored in detail. The mathematical model for carrier dynamics and performance measuring parameters are analyzed and optimized. Moreover, the number of quantum wells is incorporated gradually up to 100 and the corresponding performances are explored. It is observed that with the increase in the number of wells, photogenerated current density enhances significantly up to a saturation point and then deteriorates. A remarkable efficiency of 24.8% and more than 80% of quantum efficiency are achieved from 50 numbers of quantum wells with 79.8% of fill factor.

Retrieving Carrier Population and Collection Efficiency in CFTS/CFTSe‐Based Solar Cell Using Low‐Dimensional Multiple Nanostructures

“…Incorporation of lesser bandgap compared to bulk material provides the advantages to absorb more number of photons from the solar spectrum. [ 18,30,31 ] These interesting phenomena help researcher to achieve more than 42% efficiency theoretically. [ 32 ] In this work, two‐dimensionally confined quantum wells (QWs) are proposed as a nanostructure with bulk material.…”

“…[9][10][11][12][13][14][15][16][17] In addition to this, incorporation of nanostructure with carrier confinement increases the overall performance of solar cell as compared to bulk solar cell. [18][19][20][21] On the other hand, the performance of CFTS and CFTSe is less explored. The material possesses the capability to reduce defects and traps as compared to CZTS.…”

Kesterite Thin‐Film Solar Cell: Role of Grain Boundaries and Defects in Copper–Zinc–Tin–Sulfide and Copper–Zinc–Tin–Selenide

“…The detailed description of models and equations used in this study can be found in the supplementary material. [ 16 ] Silvaco ATLAS technology computer‐aided design (TCAD) tool is used to analyze the functioning and performance of these photovoltaic devices. [ 17 ] The simulation of these devices is carried out under an illumination spectrum power of 1 sun with air mass 1.5 global spectrum.…”

“…All the mathematical expressions for four performance measuring parameters with only traps and only defects can be found in the previous studies. [ 8,16 ] The reverse saturation current density is calculated, considering non‐radiative recombination, the presence of defects states, and trap states. Shockley–Read–Hall (SRH) recombination mechanism is applied to incorporate the effect of trap states near the middle of the forbidden gap.…”

“…Open‐circuit voltage, fill factor, and efficiency of both CZTS and CZTSe solar cell are also calculated using mathematical models discussed in our previous works. [ 8,16 ]…”