https://scholar.dgist.ac.kr/handle/20.500.11750/459 Sat, 04 Apr 2026 08:47:57 GMT 2026-04-04T08:47:57Z https://scholar.dgist.ac.kr/handle/20.500.11750/5382 Title: Optimum Substrate Temperature in One-stage Co-evaporation of Cu(ln,Ga)Se-2 Thin Films for High-efficiency Solar Cells Author(s): Kim, Chan; Rhee, Ilsu; Hwang, Dae-Kue; Kim, Dae-Hwan Abstract: One-stage co-evaporation of Cu(In,Ga)Se2 (CIGS) thin films has strong potential for wide adoption in industry because of its simplicity compared with multiple-stage processes. This study investigated the effects of substrate temperature during CIGS film growth on the efficiency of the resulting ITO/ZnO/CdS/CIGS/Mo structures. CIGS thin films were grown by using one-stage co-evaporation at substrate temperatures ranging from 525 to 550 °C. The device with a CIGS film grown at 535 °C was found to have the highest cell efficiency. In the XRD patterns, films grown at this substrate temperature had the largest texture coefficient for the (220) plane and the smallest full width at half maximum for both the (112) and the (220) planes. Other cell electrical characteristics were also largest for this substrate temperature. Thus, we conclude that the optimal morphological characteristics of CIGS thin films grown at a temperature of 535 °C are responsible for the high efficiency. Wed, 30 Nov 2011 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/5382 2011-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/5362 Title: The optical and structural properties of CuIn1-x Ga (x) Se-2 thin films fabricated with various Ga contents by using the co-evaporation technique Author(s): Jo, Hyun Jun; Kim, Dae-Hwan; Kim, Chan; Hwang, Dae-Kue; Sung, Shi-Joon; Kim, Jeong-Hwa; Bae, In-Ho Abstract: The purpose of the present study is to investigate the optical and the structural properties of CuIn 1-xGa xSe 2 (CIGS) thin films with various Ga/[In+Ga] ratios grown by using the coevaporation technique. The Ga ratios were 0, 0.15, 0.29, 0.40, 0.56, 0.73, and 1. As the Ga/[In+Ga] ratio increased, the grain size of CIGS films decreased, and the X-ray diffraction (XRD) peaks of the CIGS films progressively shifted to higher diffraction angles. In the cross-sectional scanning electron microscopy (SEM) images, the grain size of the CIGS thin films near the molybdenum electrode was smaller than it was near the CIGS surface. These results indicate that the diffusion rates of elements were different. The photocurrent (PC) spectra also showed that the band gap energy of the CIGS films increased as the Ga/[In+Ga] ratio increased. Accordingly, the short-circuit current density (J SC) linearly decreased, and the open-circuit voltage (V OC) increased and saturated at high Ga/[In+Ga] ratios (x > 0.4) due to the defects on the CIGS films surface. A correlation between the Ga/[In+Ga] ratio and the number of surface defects for the CIGS films is discussed. © 2012 The Korean Physical Society. Mon, 30 Apr 2012 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/5362 2012-04-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/5355 Title: Effect of Inorganic Nanoparticle Addition to the Hole-Collecting Buffer Layers in Polymer Solar Cells Author(s): Jeong, Jaehoon; Nam, Sungho; Kim, Joonhyeon; Woo, Sungho; Kim, Hwajeong; Kim, Youngkyoo Abstract: We investigated the in?uence of nickel oxide (NiO) nanoparticles that are incorporated into the hole-collecting buffer layer [poly(3,4- ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)] on the performance of polymer:fullerene solar cells. To understand the optimum composition of NiO nanoparticles, the composition of NiO nanoparticles was varied from 0 wt% to 23 wt%. Results showed that the optical transmittance was gradually decreased as the NiO content increased. However, the device performance (short circuit current density, fill factor, series resistance, power conversion efficiency) exhibited a two stage trend in a boundary of ∼9 wt% NiO content. This trend was in good agreement with the trend of sheet resistance in the presence of slight discrepancy owing to the different charge transport geometry. © 2012 American Scientific Publishers. Sat, 30 Jun 2012 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/5355 2012-06-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/5349 Title: Hybrid Solar Cells with In-Situ Prepared Inorganic Nanoparticles/Polymer Bulk Heterojunction Films Author(s): Kwak, Eun-Joo; Woo, Sungho; Lee, Hyena; Kim, Hwajeong; Kim, Youngkyoo Abstract: Lead sulfide (PbS) nanoparticles were generated by the in-situ reaction of lead chloride (II) and sulfur in the presence of poly (3-hexylthiophene) (P3HT) dissolved in the co-solvents. Three different reaction times were used to examine the effect of the PbS reaction conditions. The in-situ generated PbS nanoparticles in the P3HT matrix were spherical with a diameter of 15~25 nm. The P3HT:PbS composite materials were mixed with a soluble fullerene derivative ([6,6]-phenyl-C61-butyric acid methyl ester-PCBM) for the fabrication of hybrid solar cells. The hybrid (P3HT:PCBM:PbS) solar cells exhibited similar performance to each other, but their performance was better than the control (P3HT:PCBM) solar cells. In particular, the optimized hybrid solar cells showed ca. 14% improved power conversion efficiency due to the larger increase in short circuit current density (~30%). This improvement was attributed to the PbS nanoparticles acting as electron acceptors and a minor contribution from scattering effect. Copyright © 2012 American Scientific Publishers. Sun, 30 Sep 2012 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/5349 2012-09-30T15:00:00Z