We introduce coplanar stripline circuits to resolve the ultrafast photocurrent dynamics of freely suspended carbon nanotubes (CNTs) in the time domain. By applying an on-chip pump-probe laser spectroscopy, we demonstrate that CNTs, contacted by metal electrodes, exhibit a picosecond photocurrent response. We find a combination of an optically induced ultrafast displacement current, transport of...

The optoelectronic characteristics of molybdenum disulfide (MoS2)/ZnO flexible photodetectors are investigated. A red-shift effect and improved photocurrent properties of the flexible devices are demonstrated. MoS2 doping improved the photocurrent properties and conductivity. The photocurrent/dark current ratios of pure ZnO and MoS2/ZnO flexible photodetectors were 10(3) and 10(4), respectively...

The photocurrent in bilayer polymer photovoltaic cells is dominated by the exciton dissociation efficiency at donor/acceptor interface. An analytical model is developed for the photocurrent-voltage characteristics of the bilayer polymer/TiO2 photovoltaic cells. The model gives an analytical expression for the exciton dissociation efficiency at the interface, and explains the dependence of the p...

We report on the contribution of effects at the organic semiconductor-metal interfaces to dark current and to transient and continuous wave cw photocurrent in high-performance functionalized anthradithiophene ADT films deposited from solution on glass substrates with gold Au and aluminum Al electrodes. In all samples, fast sub-30 ps charge carrier photogeneration was observed under photoexcitat...

Films based on electrostatic interactions between tetracationic porphyrin and Dawson type polyoxometalate are formed by the so called layer-by-layer method. Their photovoltaic performances are investigated by photocurrent transient measurements which showed significant photocurrent response.

The large photocurrent hysteresis observed in many organometal trihalide perovskite solar cells has become a major hindrance impairing the ultimate performance and stability of these devices, while its origin was unknown. Here we demonstrate the trap states on the surface and grain boundaries of the perovskite materials to be the origin of photocurrent hysteresis and that the fullerene layers d...

We study photocurrent generation in individual suspended carbon nanotube p-n junctions using spectrally resolved scanning photocurrent microscopy. Spatial maps of the photocurrent allow us to determine the length of the p-n junction intrinsic region, as well as the role of the n-type Schottky barrier. We show that reverse-bias operation eliminates complications caused by the n-type Schottky bar...

We report a scanning photocurrent microscopy (SPCM) study of colloidal lead selenide (PbSe) quantum dot (QD) thin film field-effect transistors (FETs). PbSe QDs are chemically treated with sodium sulfide (Na2S) and coated with amorphous alumina (a-Al2O3) by atomic layer deposition (ALD) to obtain high mobility, air-stable FETs with a strongly gate-dependent conductivity. SPCM reveals a long pho...

Experimental characterization and finite-element numerical simulations of the electromagnetic interaction between random or periodic Au nanodot arrays patterned atop a silicon-on-insulator SOI photodetector and incident electromagnetic plane waves have been performed at wavelengths of 400–1100 nm. The presence of the Au nanodots is found to lead to increased electromagnetic field amplitude with...

In recent photovoltaic research, nanomaterials have offered two new approaches for trapping light within solar cells to increase their absorption: nanostructuring the absorbing semiconductor and using metallic nanostructures to couple light into the absorbing layer. This work combines these two approaches by decorating a single-nanowire silicon solar cell with an octahedral silver nanocrystal. ...