High Performance PbS Quantum Dot/Graphene Hybrid Solar Cell with Efficient Charge Extraction

Abstract

Hybrid colloidal quantum dot (CQD) solar cells are fabricated from multilayer stacks of lead sulfide (PbS) CQD and single layer graphene (SG). The inclusion of graphene interlayers is shown to increase power conversion efficiency by 9.18%. It is shown that the inclusion of conductive graphene enhances charge extraction in devices. Photoluminescence shows that graphene quenches emission from the quantum dot suggesting spontaneous charge transfer to graphene. CQD photodetectors exhibit increased photoresponse and improved transport properties. We propose that the CQD/SG hybrid structure is a route to make CQD thin films with improved charge extraction, therefore resulting in improved solar cell efficiency.

High-response hybrid quantum dots- 2D conductor phototransistors: recent progress and perspectives

“…The layer-by-layer (LbL) assembly method is most commonly used and relies on the electrostatic interaction of oppositely charged films [19]. LbL involves synthesis of separate components, which are then assembled through repeated drop-casting/spin-coating of graphene/ TMDs and QDs successively on a highly doped or undoped substrate [16,[21][22][23] depending on the device configuration of choice [24]. Figure 2 illustrates QD-bottom and graphene-bottom hybrid transistors fabricated using this method.…”

“…Colloidal QDs typically used for hybrid 2D-0D devices are made of PbS [7,[21][22][23], PbSe [26,27], or ZnO [28] QDs. PbS/PbSe QDs are generally fabricated using wet chemical synthesis methods [7,[21][22][23][26][27][28][29] that include thermal decomposition of organometallic precursors in the presence of a coordinating solvent, which provides a micelle-like ligand shell that controls the growth of the particles while ZnO QDs are grown using hydrothermal techniques [28].…”

“…PbS/PbSe QDs are generally fabricated using wet chemical synthesis methods [7,[21][22][23][26][27][28][29] that include thermal decomposition of organometallic precursors in the presence of a coordinating solvent, which provides a micelle-like ligand shell that controls the growth of the particles while ZnO QDs are grown using hydrothermal techniques [28]. The most important component of a hybrid phototransistor is the chemical structure, length, and conductivity of the ligands used during the synthesis of the QDs.…”

Interlayer coupling and the phase transition mechanism of stacked MoS2/TaS2 heterostructures discovered using temperature dependent Raman and photoluminescence spectroscopy

“…[1][2][3] Recently, prominent progress in the eld of heterojunctions has been made resulting in the development of high speed, performance and power devices. [4][5][6] Atom-thin heterojunctions as a new category of 2D semiconducting material are almost as thin, transparent and exible as other 2D heterojunctions, with a rich array of new physical phenomena. [2][3][4][5] At this point, layered twodimensional (2D) crystals such as transition metal dichalcogenides (TMDCs), graphene and hexagonal boron nitride have attracted noteworthy attention as different 2D materials that can be assembled vertically.…”

“…[4][5][6] Atom-thin heterojunctions as a new category of 2D semiconducting material are almost as thin, transparent and exible as other 2D heterojunctions, with a rich array of new physical phenomena. [2][3][4][5] At this point, layered twodimensional (2D) crystals such as transition metal dichalcogenides (TMDCs), graphene and hexagonal boron nitride have attracted noteworthy attention as different 2D materials that can be assembled vertically. Note that TMDCs are a broad family of compounds, which have layered two-dimensional (2D) crystal structures.…”