• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.330-330
• /
• 2006

The elaboration of fluorescent submicronic polymer particles exhibiting narrow particle size distribution as well as good photostability is of particular interest in various biomedical applications. In the frame of this work, labeled polystyrene latexes have been synthesized by miniemulsion polymerization using luminescent semiconductor nanoparticles (quantum dots, QD). The influence of incorporation of QDs on the polymerization kinetics as well as on the optical properties of the obtained latexes will be discussed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.270-270
• /
• 2010

4족 반도체 원소 양자점들은 원소가 가지고 있는 반도체적 성질과, 양자점에서 나타나는 quantum confinements 적인 특성 때문에 전자재료나 광학적 분야, 특히 태양전지 분야에서 그 쓰임이 대두되고 있다. 이러한 4족 반도체 원소의 양자점들을 만들기 위한 여러 방법들이 시도되고 있는데, 그 중에서 특히 절연체 박막에 4족 반도체 원소의 양자점들을 만드는 방법에는 이온주입, PVD, 그리고 CVD 를 통한 multi-layer 증착후 열처리 과정을 반드시 포함하는 Stranski- krastanov 방법이 주로 사용되고 있다. 본 실험에서는 고체원소 이온주입이라는 방법을 통해 절연체 박막의 증착과 이온주입이 한 진공용기 내에서 연속공정으로 이루어 지면서, 별도의 열처리 과정 없이 결정화된 게르마늄 양자점을 만들어 보았다. 이는 (X-ray diffraction) XRD와 Raman spectroscopy로 결정화된 게르마늄을 확인할 수 있었으며, (X-ray photoelectron spectroscopy)XPS 데이터로도 순수한 게르마늄이 표면에서 깊이 방향으로 약 $1,000\;{\AA}$ 만큼 게르마늄 양자점들이 만들어 짐을 알 수 있었다. 마지막으로 (High resolution transmittance electron microscopy) HRTEM으로 그 양자점의 크기와 분포도 그리고 결정성을 알아 보았다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2003.08a
• /
• pp.128-128
• /
• 2003

• Ceramist
• /
• v.21 no.2
• /
• pp.59-74
• /
• 2018

Imaging in the Short Wave Infrared (SWIR) provides several advantages over the visible and near-infrared regions: enhanced image resolution in in foggy or dusty environments, deep tissue penetration, surveillance capabilities with eye-safe lasers, assessment of food quality and safety. Commercially available SWIR imagers are fabricated by integrating expensive epitaxial grown III-V compound semiconductor sensors with Si-based readout integrated circuits(ROIC) by indium bump bonding Infrared image sensors made of solution-processed quantum dots have recently emerged as candidates for next-generation SWIR imagers. They combine ease of processing, tunable optoelectronic properties, facile integration with Si-based ROIC and good performance. Here, we review recent research and development trends of various application fields of SWIR image sensors and nano-materials capable of absorption and emission of SWIR band. With SWIR sensible nano-materials, new type of SWIR image sensor can replace current high price SWIR imagers.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.02a
• /
• pp.152-153
• /
• 2003

최근 양자점 (Quantum Dot-QD)에 대한 관심이 기초 물리학뿐만 아니라 광전소자 응용 측면에서 많은 주목을 끌고 있다. 특히, 자발 형성방법으로 성장시킨 양자점 (Self-assembled QD)을 이용하여 Laser Diode와 같은 광소자에 응용한 결과가 발표되고 있다. 이러한 자발형성 방법으로 성장한 양자점을 광통신에 응용하기 위해서는 발광파장을 제어할 필요성이 있다. 따라서 본 연구에서는 단거리 광통신에 응용 될 수 있는 1.3 $\mu$m 영역과 장거리 광통신에 사용하는 1.55 $\mu$m 영역으로 InAs 양자점의 발광 파장을 변조한 결과에 대하여 분석하였다. (중략)

• Journal of Electrical Engineering and information Science
• /
• v.2 no.6
• /
• pp.208-211
• /
• 1997

We have fabricated a single-electron-tunneling(SET) transistor with a dual gate geometry based on the SOI structure prepared by SIMOX wafers. The split-gate is the lower-gate is the lower-level gate and located ∼ 100${\AA}$ right above the inversion layer 2DEG active channel, which yields strong carrier confinement with fully controllable tunneling potential barrier. The transistor is operating at low temperatures and exhibits the single electron tunneling behavior through nano-size quantum dot. The Coulomb-Blockade oscillation is demonstrated at 15mK and its periodicity of 16.4mV in the upper-gate voltage corresponds to the formation of quantum dots with a capacity of 9.7aF. For non-linear transport regime, Coulomb-staircases are clearly observed up to four current steps in the range of 100mV drain-source bias. The I-V characteristics near the zero-bias displays typical Coulomb-gap due to one-electron charging effect.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.4
• /
• pp.857-862
• /
• 2009

We model lattice-mismatched group III-V semiconductor $In_{x}Ga_{1-x}$ alloys with the three-parameter anharmonic Kirkwood-Keating potential, which includes realistic distortion effect by introducing anharmonicity. Although the potential parameters were determined based on optical properties of the binary parent alloys InAs and GaAs, simulated dielectric functions, reflectance, and Raman spectra of alloys agree excellently with experimental data for any arbitrary atomic composition. For a wide range of atomic composition, InAs- and GaAs-bond retain their respective properties of binary parent crystals despite lattice and charge mismatch. It implies that use of the anharmonic Kirkwood-Keating potential may provide an optimal model system to investigate diverse and unique optical properties of quantum dot heterostructures by circumventing potential parameter searches for particular local structures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.175-176
• /
• 2006

Zeolite의 이온교환 특성과 균일한 기공과 결정 모양을 가지는 구조적 특성을 이용하여 CdS 양자점 클러스터를 합성하였다. 합성된 CdS-Zeolite는 구조적으로 안정된 나노 크기의 새로운 반도체 물질이 된다. 또한 Zeolite 결정들이 유리판에 밀집하여 배열되는 경향을 이용하므로 CdS 양자점이 합성된 제올라이트를 기판에 정렬, 박막을 형성한다. CdS-Zeolite 결정 박막은 SEM 측정을 통해 구조와 표면 정렬 상태를 알고, photoluminescence 측정으로 양자점 특성의 발광 파장을 가짐을 알 수 있다.

• Journal of the Semiconductor & Display Technology
• /
• v.16 no.2
• /
• pp.15-18
• /
• 2017

In this study, we have studied the characteristics of the organic photodiode varying due to the blending conditions of the quantum dots (QDs). The active layer of the photodiode was formed with poly (3-hexylthiophene) and phenyl-C61-butyric acid methyl ester, and CdSe QDs with and without ZnS shell were blended in the active layer. The photodiode with CdSe/ZnS QDs showed the highest power conversion efficiency (PCE) and short-circuit current (Jsc). The performance change of the organic photodiode by X-ray irradiation was also measured. Regardless of X-ray irradiation conditions, the photodiode with CdSe/ZnS QDs showed better stability than other cases.

• 한국전자현미경학회:학술대회논문집
• /
• 2005.11a
• /
• pp.85-88
• /
• 2005