title: Growth and characterization of Cu(In,Ga)Se2 thin films by nanosecond and femtosecond pulsed laser deposition.
abstract: In this work, CuIn1 - x Ga x Se2 (CIGS) thin films were prepared by nanosecond (ns)- and femtosecond (fs)-pulsed laser deposition (PLD) processes. Different film growth mechanisms were discussed in perspective of the laser-produced plasmas and crystal structures. The fs-PLD has successfully improved the inherent flaws, Cu2 - x Se, and air voids ubiquitously observed in ns-PLD-derived CIGS thin films. Moreover, the prominent antireflection and excellent crystalline structures were obtained in the fs-PLD-derived CIGS thin films. The absorption spectra suggest the divergence in energy levels of radiative defects brought by the inhomogeneous distribution of elements in the fs-PLD CIGS, which has also been supported by comparing photoluminescence (PL) spectra of ns- and fs-PLD CIGS thin films at 15 K. Finally, the superior carrier transport properties in fs-PLD CIGS were confirmed by fs pump-probe spectroscopy and four-probe measurements. The present results indicate a promising way for preparing high-quality CIGS thin films via fs-PLD.
authors: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Shih-Chen
authors: SC
authors: Chen
authors: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Dan-Hua
authors: DH
authors: Hsieh
authors: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Hsin
authors: H
authors: Jiang
authors: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Yu-Kuang
authors: YK
authors: Liao
authors: Department of Photonic Engineering, Yuan-Ze University, Taoyuan 32003, Taiwan.
authors: Fang-I
authors: FI
authors: Lai
authors: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Chyong-Hua
authors: CH
authors: Chen
authors: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Chih Wei
authors: CW
authors: Luo
authors: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Jenh-Yih
authors: JY
authors: Juang
authors: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors: Yu-Lun
authors: YL
authors: Chueh
authors: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Kaung-Hsiung
authors: KH
authors: Wu
authors: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors: Hao-Chung
authors: HC
authors: Kuo
keywords: CIGS; Femtosecond; Photoluminescence; Pulsed laser deposition; Pump probe