A novel solution-processable non-fullerene electron acceptor 6,6'-(5,5'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(thiophene-5,2-diyl))bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione) (DPP1) based on fluorene and diketopyrrolopyrrole conjugated moieties was designed, synthesized and fully characterized. DPP1 exhibited excellent solubility and high thermal stability ...

This paper introduces the fundamental physical characteristics of organic photovoltaic (OPV) devices. Photoelectric conversion efficiency is crucial to the evaluation of quality in OPV devices, and enhancing efficiency has been spurring on researchers to seek alternatives to this problem. In this paper, we focus on organic photovoltaic (OPV) devices and review several approaches to enhance the ...

In this work, the photocatalytic disinfection of Escherichia coli (E. coli) using dual layer ceramic wafers, prepared by a simple and low-cost technique, was investigated. Heterojunction wafers were prepared by pressing TiO2 and WO3 powders together into 2 layers within a single, self-supported monolith. Data modelling showed that the heterojunction wafers were able to sustain the formation of ...

We investigated cyanine heterojunction photovoltaic devices using carbocyanine dyes as donors and buckminsterfullerene (C60) as acceptor. In particular, we focused on the influence of cyanine counterions on the photovoltaic device characteristics. It was found that counterions can be displaced in the applied electric field and give rise to important hystereses in the current-voltage characteris...

Recently, negative differential resistance devices have attracted considerable attention due to their folded current-voltage characteristic, which presents multiple threshold voltage values. Because of this remarkable property, studies associated with the negative differential resistance devices have been explored for realizing multi-valued logic applications. Here we demonstrate a negative dif...

The interfacial reaction and energy level alignment at the Si/transition metal oxide (TMO, including MoO3-x, V2O5-x, WO3-x) heterojunction are systematically investigated. We confirm that the interfacial reaction appears during the thermal deposition of TMO, with the reaction extent increasing from MoO3-x, to V2O5-x, and to WO3-x. The reaction causes the surface oxidation of silicon for faster ...

In contrast to the numerous reports on narrow-bandgap heterojunctions on silicon, such as strained Si1 xGex on silicon, there have been very few accounts of wide-bandgap semiconducting heterojunctions on silicon. Here, we present a wide-bandgap heterojunction—between titanium oxide and crystalline silicon—where the titanium oxide is deposited via a metal-organic chemical vapor deposition proces...

This paper focuses on nano-morphology-controlled small-molecule organic solar cells without solvent treatment for high power-conversion efficiencies (PCEs). The maximum high PCE reaches up to 7.22% with a bulk-heterojunction (BHJ) thickness of 320 nm. This high efficiency was obtained by eliminating solvent additives such as 1,8-diiodooctane (DIO) to find an alternative way to control the domai...

The source resistance of a heterojunction field-effect transistor ~HFET!, whose reduction is mandatory for high-performance devices, consists of an ohmic contact resistance and an access resistance. The access region is located between the geometrical source and the geometrical source side of the gate contact. By means of a quantum-mechanical modeling program, the effect of changes in layer str...

We report the first observation of piezotronic effect on the output voltage of a flexible heterojunction solar cell. The solar cell was fabricated by contacting poly(3-hexylthiophene) (P3HT) with one end of a ZnO micro/nanowire to form a p-n heterojunction on a flexible polystyrene (PS) substrate. The open-circuit voltage V(oc) of the solar cell was characterized by tuning the strain-induced po...