Sungkyunkwan University

About: Sungkyunkwan University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Graphene. The organization has 28229 authors who have published 56428 publications receiving 1352733 citations. The organization is also known as: 성균관대학교.

Stability Issues on Perovskite Solar Cells

Abstract: Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3) and formamidinium lead iodide (HC(NH2)2PbI3) show superb opto-electronic properties. Based on these perovskite light absorbers, power conversion efficiencies of the perovskite solar cells employing hole transporting layers have increased from 9.7% to 20.1% within just three years. Thus, it is apparent that perovskite solar cell is a promising next generation photovoltaic technology. However, the unstable nature of perovskite was observed when exposing it to continuous illumination, moisture and high temperature, impeding the commercial development in the long run and thus becoming the main issue that needs to be solved urgently. Here, we discuss the factors affecting instability of perovskite and give some perspectives about further enhancement of stability of perovskite solar cell.

Multinational Randomized Phase III Trial With or Without Consolidation Chemotherapy Using Docetaxel and Cisplatin After Concurrent Chemoradiation in Inoperable Stage III Non–Small-Cell Lung Cancer: KCSG-LU05-04

Abstract: Purpose To determine the efficacy of consolidation chemotherapy (CC) with docetaxel and cisplatin (DP) after concurrent chemoradiotherapy (CCRT) with the same agents in locally advanced non–small-cell lung cancer (LA-NSCLC). Patient and Methods Patients were randomly assigned to either CCRT alone (observation arm) or CCRT followed by CC (consolidation arm). CCRT with docetaxel (20 mg/m2) and cisplatin (20 mg/m2) was administered every week for 6 weeks with a total dose of 66 Gy of thoracic radiotherapy in 33 fractions. In the consolidation arm, patients were further treated with three cycles of DP (35 mg/m2 each on days 1 and 8, every 3 weeks). The primary end point was 40% improvement in progression-free survival (PFS) compared with observation. Results From October 2005 to April 2011, 437 patients were randomly assigned. Seventeen patients did not start CCRT as a result of consent withdrawal or ineligibility reasons after random assignment, leaving 420 patients for this analysis (n = 211 for observation...

P-Type Polymer-Hybridized High-Performance Piezoelectric Nanogenerators

Abstract: Enhancing the output power of a nanogenerator is essential in applications as a sustainable power source for wireless sensors and microelectronics. We report here a novel approach that greatly enhances piezoelectric power generation by introducing a p-type polymer layer on a piezoelectric semiconducting thin film. Holes at the film surface greatly reduce the piezoelectric potential screening effect caused by free electrons in a piezoelectric semiconducting material. Further- more, additional carriers from a conducting polymer and a shift in the Fermi level help in increasing the power output. Poly(3-hexylthiophene) (P3HT) was used as a p-type polymer on piezoelectric semiconducting zinc oxide (ZnO) thin film, and phenyl-C61-butyric acid methyl ester (PCBM) was added to P3HT to improve carrier transport. The ZnO/P3HT:PCBM-assembled piezoelectric power generator demonstrated 18-fold enhancement in the output voltage and tripled the current, relative to a power generator with ZnO only at a strain of 0.068%. The overall output power density exceeded 0.88 W/cm 3 , and the average power conversion efficiency was up to 18%. This high power generation enabled red, green, and blue light-emitting diodes to turn on after only tens of times bending the generator. This approach offers a breakthrough in realizing a high-performance flexible piezoelectric energy harvester for self-powered electronics.