The effect of external optical feedback on an InAs/GaAs quantum dot passively mode-locked laser is investigated. The RF linewidth narrows from 8 KHz in the free-running situation to a value as low as 350 Hz under relatively low feedback. The RF linewidth characterization under resonant feedback at a multiple of the laser cavity length validates the prediction of a previous numerical simulation....

Semiconductor nanowires (NWs) are very promising building blocks for future electronic and optoelectronic devices. Realizing this, nevertheless, requires overcoming several important challenges, such as control and evaluation of doping levels in NWs. Due to the nanoscale nature of NWs, characterization techniques, such as Hall effect measurements and four-point probes, used conventionally for t...

The electronic and photoconductive characteristics of CdTe nanowire-based field effect transistors were studied systematically. The electrical characterization of a single CdTe nanowire FET verifies p-type behavior. The CdTe NW FETs respond to visible-near infrared (400-800 nm) incident light with a fast, reversible and stable response characterized by a high responsivity (81 A W(-1)), photocon...

The photoconductive terahertz measurement technique was used for measurement of the radiation pattern from thick metal slits. Picosecond pulses were generated and detected by an ultrafast optoelectronic technique using a femtosecond pulse laser and a subpicosecond photoconductor. Photoconductive sampling measurements of the polarization-dependent diffraction of the picosecond electromagnetic pu...

Colloidal core-shell semiconductor nanocrystals form an important class of optoelectronic materials, in which the exciton wave functions can be tailored by the atomic configuration of the core, the interfacial layers, and the shell. Here, we provide a trustful 3D characterization at the atomic scale of a free-standing PbSe(core)-CdSe(shell) nanocrystal by combining electron microscopy and discr...

The exceptional electronic and optical properties of high-quality organic crystals are well known and have been exploited in active electronic and optoelectronic devices such as field-effect transistors, photodetectors and optical modulators. This paper describes a room temperature method for in-plane growth of organic crystal needles from initially amorphous thin films of the molecular organic...

We demonstrate experimentally a chemical codoping approach that would simultaneously narrow the band gap and control the band edge positions of TiO2 semiconductors. It is shown that a sequential doping scheme with nitrogen (N) leading the way, followed by phosphorus (P), is crucial for the incorporation of both N and P into the anion sites. Various characterization techniques confirm the format...

Group-IV nanocrystals have emerged as a promising group of materials that extends the realm of application of bulk diamond, silicon, germanium and related materials beyond their traditional boundaries. Over the last two decades of research, their potential for application in areas such as optoelectronic applications and memory devices has been progressively unraveled. Nevertheless, new challeng...

III-V semiconductor nanocrystals are of considerable interest due to their extensive applications in the optoelectronic and biomedical fields. In order to meet the practical use, the convenient and scalable production of III-V narrow-disperse nanocrystals is inspiring. We report an efficient and rapid method of preparing InP nanocrystals using a wetchemical redox synthetic approach with a nonco...