Highly Efficient Inorganic–Organic Heterojunction Solar Cells Based on Polymer and CdX (X = Se, Te) Quantum Dots: An Insight from a Theoretical Study

Abstract

Using the density functional method, we explore the potentiality of the recently synthesized CdX (X = Se, Te) QD/P3HT composites in solar energy conversion devices. Our study reveals that inorganic/organic hybrid CdXQD/P3HT nanocomposites with larger-size CdX QDs exhibit type-II band alignment, suggesting an efficient charge separation upon photoexcitation. But for smaller-size QDs, the composites show type-I band alignment that are devoid of charge separation and thus are not suitable for solar cell applications. To remove this obstacle, we focus on the chemical modification to polymer P3HT. The substitution of hydrogen at the β-position of each thiophene ring of polymer by the electron-withdrawing group (CN) results in a type-II band alignment and achieves spatial charge separation even for smaller-size quantum dots (QDs). Finally, we calculated the power conversion efficiency (PCE) of CdXQDand CN-functionalized P3HT nanocomposites. The maximum calculated PCE value of 10.82% is achieved, which makes the nanocomposites highly competitive with other reported heterojunction solar cells.

Interfacial Charge Transfer in Photoexcited QD-Molecule Composite of Tetrahedral CdSe Quantum Dot Coupled with Carbazole

“…The self-consistent charge density functional tight-binding (SCC-DFTB) method − was employed to simulate these T1, T2, and T3 CdSe QDs. The Cd-chalcogenide parameter set along with the mio-0-1 parameter set were used in this work. , The Cd-chalcogenide parameter set was successfully used in different systems previously. − We first optimized the outer shell (ligands) of the QDs by imposing a constraint on the Cd m Se n core, followed by reoptimizing the full CdSe QDs. The optimized Cd m Se n cores maintained their tetrahedral shape; however, the apex Cd–Se bonds are only slightly tilted.…”

Theoretical prediction of a type-II BP/SiH heterostructure for high-efficiency electronic devices

“…In addition, from a practical viewpoint, the power conversion efficiency (PCE) of a heterostructure is an important point used to evaluate the util-ization efficiency of sunlight. [63][64][65] The PCE can be obtained by the method of Scharber et al 66 However, in this work, we mainly focus on the electronic properties and band alignment of the BP/SiH heterostructure, as well as its controllable electronic properties under an electric field. The optoelectronic properties and the PCE will be focused on in our future work.…”

Influence of chemical composition and doping on optical properties of thallium selenide layers prepared by adsorption/diffusion method

“…Polymers modified by thin films of binary d-metal chalcogenides belong to the composite materials as well. These composites promise to be valuable in solar energy conversion [1,2], thermoelectrics [3,4], photocatalysis [5], photodetectors [6], light-emitting diodes [7] and so on. Group III metal (Ga, In and Tl) composite materials binary or ternary compounds combined with group VI nonmetals (S, Se and Te) have very important and unique physical properties to technology and modern science.…”