The chemistry and energetics of the interface between metal halide perovskite and atomic layer deposited metal oxides

The chemistry of the interface between the metal halide perovskite absorber and the charge transport layer affects the performance and stability of metal halide perovskite solar cells (PSCs). The literature provides several examples of poor PSC conversion efficiency values, when electron transport layers (ETLs), such as SnO2 and TiO2, are...

A High-Resolution Thin-Film Fingerprint Sensor Using a Printed Organic Photodetector

Organic photodetectors (OPDs) have attracted much attention in recent years, due to their promise in large-area light sensing applications. Here, high-resolution slot-die-coated large-area bulk heterojunction organic photodiode (OPD) arrays are reported. The OPD uses a novel electron transport layer, indium gallium zinc oxide in combination with...

Low-Temperature Plasma-Assisted Atomic-Layer-Deposited SnO2 as an Electron Transport Layer in Planar Perovskite Solar Cells

In this work, we present an extensive characterization of plasma-assisted atomic-layer-deposited SnO2 layers, with the aim of identifying key material properties of SnO2 to serve as an efficient electron transport layer in perovskite solar cells (PSCs). Electrically resistive SnO2 films are fabricated at 50 °C, while a SnO2 film with a low...

Device physics of white polymer light-emitting diodes

The charge transport and recombination in white-emitting polymer light- emitting diodes (PLEDs) are studied. The PLED investigated has a single emissive layer consisting of a copolymer in which a green and red dye are incorporated in a blue backbone. From single-carrier devices the effect of the green- and red-emitting dyes on the hole and...

The effect of ketone defects on the charge transport and charge recombination in polyfluorenes

The effect of on-chain ketone defects on the charge transport of the polyfluorene derivative poly(9,9-dioctylfluorene) (PFO) is investigated. Using MoO3 as ohmic hole contact, the hole transport in a pristine PFO diode is observed to be limited by space-charge, whereas fluorenone contaminated PFO (PFO-F) is shown to be trap limited by the...

Electron-enhanced hole injection in blue polyfluorene-based polymer light-emitting diodes

It has recently been reported that, after electrical conditioning, an ohmic hole contact is formed in poly(9,9-dioctylfluorene) (PFO)-based polymer light-emitting diodes (PLED), despite the large hole-injection barrier obtained with a poly(styrene sulfonic acid)-doped poly(3,4-ethylenedioxythiophene) (PEDOTPSS) anode. We demonstrate that the...

Mechanistic study of excitation energy transfer in dye-doped PPV polymers

The mechanism of excitation energy transfer is studied using host-guest systems consisting of green and yellow emitting poly(phenylene vinylene) (PPV) based polymers into which red emitting dyes are dispersed. The photoluminescence from such polymer-dye systems is studied in the steady-state and time resolved. Furthermore, the...

Local temperature measurement and Kapitza boundary resistance

A calculation of the Kapitza boundary resistance between harmonic solids has been noted previously (Little, Can. J. Phys. 37 (1959) 334; Leung and Young, Phys. Rev. B 36 (1987) 4973) to lead to apparently paradoxical results in the limit of identical solids: instead of vanishing, the resistance tends to a finite limit. We resolve this paradox by...