Authors: David J Hwang Seungkuk Kuk Zhen Wang Shi Fu Tao Zhang Gayeon Kim Won Mok Kim Jeunghyun Jeong
Publish Date: 2016/12/21
Volume: 123, Issue: 1, Pages: 55-
Abstract
Laser scribing technology has been actively developed for thinfilm solar cell fabrication taking a number of advantages over mechanical scribing Its noncontact processing nature enables reliable and precise scribing processes In particular it is almost unavoidable to use laser scribing method for fabricating highquality flexible thinfilm solar cells Despite the fundamental merits that laser scribing can offer still a number of challenges should be addressed in order to replace the mechanical counterpart for wider range of thinfilm solar cells In this study we explore optimal laser scribing conditions for copper–indium–gallium–selenide CIGS thinfilm solar cells especially based on flexible polyimide PI substrate in close comparison with that based on sodalime glass substrate Picosecondpulsed laser of repetition rate up to 100 kHz and wavelength of 532 nm ~12 ps temporal pulse width was mainly tested and scribing speed in the range of 001–1 m/s was examined with a few different laser focal spot diameters 27 34 and 62 μm Main focus of this study is in understanding distinct laser scribing mechanisms for flexible substrate configurations thereby finding out intrinsic optimal processing parameters One of the most critical requirements is to prevent possible damage or deformation of underlying thinfilm layers or PI substrate Effect of microstructures of thin films in particular Mo and CIGS on the scribing behavior was also examined In order to further improve the performance of the scribing process and reduce the laser power budget as well mild gas injection scheme was testedThis work was supported by the Korea Institute of Energy Technology Evaluation and Planning KETEP and the Ministry of Trade Industry Energy MOTIE of the Republic of Korea 20158520000060 GY Kim WM Kim and JH Jeong acknowledge the support by the Technology Development Program to Solve Climate Changes of the National Research Foundation NRF funded by the Ministry of Science ICT Future Planning 2016M1A2A2936782 The electron microscope analysis was performed at the Center for Functional Nanomaterials Brookhaven National Laboratory which is supported by the US Department of Energy Office of Basic Energy Sciences under Contract No DEAC0298CH10886
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