Potential well

About: Potential well is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 30812 citations.

Optical properties of porous silicon

Abstract: The optical properties of porous Si films produced by electrochemical dissolution of Si are reviewed. From measurements of the optical absorption spectra of a number of samples, an inverse relationship between the optical gap energy and the average nanoparticle size is obtained demonstrating for the first time the quantum confinement of electron-hole pairs in porous Si. Two different sources of photoluminescence in anodized Si have been identified.

Heterostructure including light generating structure contained in potential well

Abstract: A light emitting heterostructure and/or device in which the light generating structure is contained within a potential well is provided. The potential well is configured to contain electrons, holes, and/or electron and hole pairs within the light generating structure. A phonon engineering approach can be used in which a band structure of the potential well and/or light generating structure is designed to facilitate the emission of polar optical phonons by electrons entering the light generating structure. To this extent, a difference between an energy at a top of the potential well and an energy of a quantum well in the light generating structure can be resonant with an energy of a polar optical phonon in the light generating structure material. The energy of the quantum well can comprise an energy at the top of the quantum well, an electron ground state energy, and/or the like.

Observation of lateral confinement effect in Ge quantum wires self‐aligned at step edges on Si(100)

Abstract: Spontaneous formation of step‐edge Ge quantum wires and lateral quantum confinement effect are clearly observed in Si submonolayer‐Ge/Si heterostructures grown on Si(100). By depositing submonolayer equivalent Ge (Q), the Ge atoms are found to line up in a wire‐like fashion at the 〈011〉 step edges as revealed by plan‐view transmission electron microscopy. Photoluminescence (PL) peak energy shift with Q due to lateral quantum confinement of holes is clearly observed, and PL features characteristic of the quasi‐one‐dimensional system are also addressed.

Different Contributions of Aliphatic and Conjugated Organic Cations to Both the Crystal and Electronic Structures: Three Hybrid Iodoargentates Showing Two Isomers of the (AgI2)– Chain

Abstract: Three new hybrid iodoargentates (H2pipe)0.5(α-AgI2) (1), (Me2teda)0.5(α-AgI2) (2), and (H2dpe)0.5(β-AgI2) (3) have been synthesized under solvothermal conditions, whereby the aliphatic organic cations (H2pipe)2+ and (Me2teda)2+ (pipe = piperazine, teda = triethylenediamine) and the conjugated organic cation (H2dpe)2+ [dpe = 1,2-di(4-pyridyl)ethylene] exhibit different contributions to both the crystal and electronic structures. The (H2pipe)2+ and (Me2teda)2+ cations direct the formation of α-type (AgI2)– polyanionic chains and influence the bandgaps of 1 and 2 indirectly by modulating the iodoargentate anionic structures. By contrast, the (H2dpe)2+ cation directs the formation of a novel β-type (AgI2)– chain and changes the bandgap of 3 directly to make up the bottom of the conduction band. From 1 and 2 to 3, a direct to indirect bandgap transformation and reduced bandgap can be observed (3.74, 2.88, and 1.99 eV for 1–3, respectively). Relative to the bandgap of bulk AgI2, the bandgaps of 1 and 2 show a blueshift as a result of the quantum confinement effect, whereas the bandgap of 3 shows a redshift owing to the direct participation of the conjugated cation (H2dpe)2+ in adjusting the bandgap.