Se‐Woong Baek
고려대학교 융합화공시스템학부 · 재료과학
이 교수의 연구실은 광학적 및 전기적 특성을 통합한 나노소재 기반의 고성능 태양전지와 광검출기 기술을 주요 연구 분야로 삼고 있습니다. 특히 금속 나노입자, 쿨롱 양자점(CQD), 플라스몬 입자 등을 활용해 태양광 수확 효율을 극대화하고, 적외선 영역까지의 광응답을 확장하는 데 초점을 맞추고 있습니다. 또한, 전도성 고분자 및 홀 수송층을 통한 장기 안정성 향상 기술 개발도 함께 진행 중입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
In this report, we propose a metal-metal core-shell nanocube (NC) as an advanced plasmonic material for highly efficient organic solar cells (OSCs). We covered an Au core with a thin Ag shell as a scattering enhancer to build Au@Ag NCs, which showed stronger scattering efficiency than Au nanoparticles (AuNPs) throughout the visible range. Highly efficient plasmonic organic solar cells were fabricated by embedding Au@Ag NCs into an anodic buffer layer, poly(3,4-ethylenedioxythiophene):poly(styren
In this report, plasmonic effects in organic photovoltaic cells (OPVs) are systematically analyzed using size-controlled silver nanoparticles (AgNPs, diameter: 10 ~ 100 nm), which were incorporated into the anodic buffer layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The optical properties of AgNPs tuned by size considerably influence the performance levels of devices. The power conversion efficiency (PCE) was increased from 6.4% to 7.6% in poly[N-9-hepta-decanyl-2,7
Colloidal quantum dots (CQDs) can be used to extend the response of solar cells, enabling the utilization of solar power that lies to the red of the bandgap of c-Si and perovskites. To achieve largely complete absorption of infrared (IR) photons in CQD solids requires thicknesses on the micrometer range; however, this exceeds the typical diffusion lengths (≈300 nm) of photoexcited charges in these materials. Nanostructured metal back electrodes that grant the cell efficient IR light trapping in
Abstract Emerging semiconducting materials show considerable promise for application in the development of next‐generation optoelectronic devices. In particular, broadband light detection is crucial in various applications, including multispectral imaging and cognition. Therefore, tuning the physical properties of semiconductors and thereby building an efficient heterojunction are important for achieving a high‐performance photodetection device. In this study, a heavy p‐type colloidal quantum do
In this report, we explore the underlying mechanisms by which doped organic thin films as a top hole-selective layer (HSL) improve the performance and stability of colloidal quantum dot (CQD)-based solar cells.
Abstract Infrared (IR) optoelectronics have become important owing to their various applications, such as recognition, autonomous driving, and quantum communications. In particular, detection beyond 1400‐nm wavelength in the shortwave IR (SWIR) spectrum (i.e., 1550 nm) is important for eye safety, and long‐range communication. Recently, group III–V (InAs or InSb) colloidal quantum dots (CQDs) have attracted considerable interest due to their broadband optical tunability and toxic‐elements (Pb an
Solution-processed low-bandgap semiconductors are crucial to next-generation infrared (IR) detection for various applications, such as autonomous driving, virtual reality, recognitions, and quantum communications. In particular, III-V group colloidal quantum dots (CQDs) are interesting as nontoxic bandgap-tunable materials and suitable for IR absorbers; however, the device performance is still lower than that of Pb-based devices. Herein, a universal surface-passivation method of InAs CQDs enable
Metal nanoparticles are demonstrated to boost the internal quantum efficiency (IQE) of organic solar cells (OSCs), even without a notable plasmonic optical gain. A hybrid layer platform in combination with silver nanoparticles (AgNPs) and a polyethylenimine‐ethoxylated (PEIE) layer maximize the IQE of the OSCs to nearly 100%, yielding a power conversion efficiency (PCE) of 10.1% in the OSCs. 2D surface characterization confirmed that the AgNPs provide a short path and funneled charge carriers to
Abstract Solution‐processed ternary‐compound semiconductor AgBiS 2 colloidal quantum dots (CQDs) are promising light‐absorbing materials owing to their nontoxicity and high absorption coefficient (>10 6 cm −1 ). However, rational strategies to passivate multi‐facet of ternary‐compound CQDs and manufacture stable CQD inks have not yet been proposed. In this paper, a ligand passivation strategy is proposed using a solution‐phase ligand exchange method. A quadruple‐ligand ensemble is employed to
A new configuration of a plasmonic quantum dots solar structure is proposed. Gold-silver core-shell metal nanoparticles (Au@Ag NCs) are incorporated into the TiO2 layer (Au@Ag NCs-HL) of PbS-based solar cells. The TiO2 layer enables the Au@Ag NCs to have broad plasmonic responses and the external quantum efficiency and absorption of the plasmonic devices are significantly enhanced. The electrical performance of the solar cells is also improved.
Extended shortwave infrared (eSWIR) photodetectors that employ solution-processable semiconductors have attracted attention for use in applications such as ranging, night vision, and gas detection. Colloidal quantum dots (CQDs) are promising materials with facile bandgap tunability across the visible-to-mid-infrared wavelengths. However, toxic elements, such as Hg and Pb, and the slow response time of CQD-based IR photodetectors, limit their commercial viability. This article presents a novel eS
Efficient infrared (IR) optoelectronic devices, crucial for emerging sensing applications and also for solar energy harvesting, demand high-conductivity IR-transparent electrodes. Here we present a new strategy, one based on oxide/metal/oxide multilayers, that enables highly transparent IR electrodes. Symmetry breaking in the oxide stack leads to broad and high transmittance from visible to IR wavelengths, while a low refractive index doped oxide as a front layer boosts IR transmittance. The com
A novel self-charging platform is proposed using colloidal-quantum-dot (CQD) photovoltaics (PVs) via the near-infrared (NIR) band for low-power electronics. Low-bandgap CQDs can convert invisible NIR light sources to electrical energy more efficiently than wider spectra because of reduced thermalization loss. This energy-conversion strategy via NIR photons ensures an enhanced photostability of the CQD devices. Furthermore, the NIR wireless charging system can be concealed using various colored a
Broadband optoelectronics, which extend from the UV to IR regions, are crucial for imaging, autonomous driving, and object recognition. In particular, photon detection efficiency relies significantly on semiconductor properties, such as absorption coefficients and electron-hole pair generation rate, which can be optimized by designing a suitable p-n junction. In this study, we devise giant PbS colloidal quantum dots (G-PbS CQDs) that exhibit high absorption coefficients and broadband absorption.