The effect of graphene quantum dots/ ZnS co‐passivation on enhancing the photovoltaic performance of CdS quantum dot sensitized solar cells

Abstract

The effect of graphene quantum dots (GQDs) as a passivating layer for cadmium sulfide (CdS) quantum dot-sensitized solar cell (QDSSC) has been investigated. GQDs were prepared by the liquid exfoliation method. The optical properties of GQDs were studied by UV-Vis and photoluminescence spectroscopies. The morphology of GQDs was studied by transmission emission morphology (TEM) analysis. Further, the photoexcitation behavior of GQDs has been studied in detail using emission spectroscopy and its effect on the photovoltaic performance of CdS QDSSC has been explored using J-V analysis. The efficacy of GQDs as passivation layer over the CdS loaded titanium dioxide (TiO 2 ) photoanode in QDSSC is high and thereby improved the open-circuit voltage (V oc ) (555 mV) compared to zinc sulfide (ZnS) passivated QDSSC (509 mV). As a result, the photoconversion efficiency (PCE) of GQD-passivated QDSSC is relatively enhanced up to 25% higher than that of ZnS-passivated QDSSC under similar conditions. A high PCE of 4.26% has been achieved for GQD/ZnS co-passivated QDSSC, which is 31% higher than ZnS-passivated QDSSC. Besides, the impedance analysis revealed low internal resistance and high charge recombination resistance in the GQD-passivated QDSSC when compared to other cells. The presence of GQD layer suppressed the recombination with high electron transport and thereby improved the PCE of QDSSC. The present study shows the possibility of using GQDs as an interfacial passivation layer between the sensitizer and electrolytes for enhancing the photovoltaic performance of CdS-based QDSSCs.

Advances in the Use of Atomic Force Microscopy as a Diagnostic Tool for Solar Cells Characterization: From Material Design to Device Applications

“…[87] A lot of other similar studies where AFM played a major role in the characterization of QDSSCs have been reported. [88][89][90][91][92] Figure 4 depicts a simplified schematic of QD intermediate band solar cells. In an investigation which was focused at formulating stacks of QD with trivial strain for intermediate band solar applications, AFM was applied to facilitate the establishment of improved uniformity in QD size distribution and areal density which was accomplished through vertical ordering of the dots successively with the objective of achieving strain compensation in the dot layers.…”

“…[ 87 ] A lot of other similar studies where AFM played a major role in the characterization of QDSSCs have been reported. [ 88–92 ]…”

Improved Performance of QDSSCs Can Be Achieved by Constructing a Transparent Anatase TiO2@MWCNT Photoanode Based on the Bionic Mountain Lotus

“…As a result, they are highly promising emerging photovoltaic devices . However, despite the theoretical power conversion efficiency of QDSSCs reaching 66%, their current practical efficiency (15%) falls far below this value, indicating substantial room for improvement. , Furthermore, they open up new potential applications in areas such as architectural glass, automotive glass, and electronic devices, thereby creating new market opportunities for solar panel deployment in these domains. − …”

Interface Regulation and Properties of Transparent Anatase TiO2 Photoanode Quantum Dot-Sensitized Solar Cells

“…If transparent solar cell glass can be commercialized, the light that has not been converted into electricity can be used for lighting. With the increasing demand for solar cells, the investment in the research and development of new transparent QDSSCs is also increasing. , The slow development of transparent photoanodes has become a problem that must be faced. TiO 2 is a commonly used wide-band-gap semiconductor in solar cell photoanodes .…”