We investigated the optical properties of Ge nanocrystals surrounded by Ge3N4. The broad emission ranging from infrared to blue is due to the dependence on the crystal size and preparation methods. Here, we report high resolution Photoluminescence (PL) attributed to emission from individual Ge nanocrystals (nc-Ge) spatially resolved using micro-photoluminescence and detailed using temperature a...

A composite of oxazine and cyclodextrin-modified carbon nanotubes (CNT-CDs) was prepared to enhance the photoluminescence of carbon nanotubes. The results show that there is a sensitizing effect of oxazine on the photoluminescence of CNT-CDs, which is probably due to energy transfer between organic molecule and CNT-CDs. However, no sensitizing effect on the photoluminescence of CNT with carboxy...

Photoluminescence excitation (PLE) spectroscopy of single-walled carbon nanotubes (SWNTs) has been extensively studied for characterization of their unique electronic properties due to the one-dimensionality. The precise evaluation of exciton transition energy is essential for experimental assignments of optical absorption, photoluminescence, and resonant Raman scatterings. Here, several experi...

The carrier dynamics in strain-induced InGaAsP/InP quantum dots (QDs) is investigated by time-resolved photoluminescence and continuous-wave photoluminescence. The stressor QDs are fabricated by depositing self-assembled InAs islands (or stressor islands) on top of a near-surface InGaAsP/InP quantum well (QW). The temporal behaviour of the QD photoluminescence transients are observed to exhibit...

Amorphous silicon quantum dots (a-Si QDs) were grown in a silicon nitride film by plasma enhanced chemical vapor deposition. Transmission electron micrographs clearly demonstrated that a-Si QDs were formed in the silicon nitride. Photoluminescence and optical absorption energy measurement of a-Si QDs with various sizes revealed that tuning of the photoluminescence emission from 2.0 to 2.76 eV i...

An investigation of the photoinduced fluorescence enhancement (PFE) behavior of CdSe/ZnS core/shell quantum dots deposited at low densities, under anhydrous and controlled water humidity, under oxygen or argon, is presented. The photoluminescence properties of CdSe/ZnS QDs are highly dependent upon the local gaseous environment. Under anhydrous conditions, under either oxygen or argon, there wa...

Tuning the emission energy of graphene quantum dots (GQDs) and understanding the reason of tunability is essential for the GOD function in optoelectronic devices. Besides material-based challenges, the way to realize chemical doping and band gap tuning also pose a serious challenge. In this study, we tuned the emission energy of GQDs by substitutional doping using chlorine, nitrogen, boron, sod...