Method for on-line monitoring of preparation of copper indium gallium selenide absorption layer

Abstract

The invention discloses a method for on-line monitoring of preparation of a copper indium gallium selenide (CIGS) absorption layer. In a growing process of the CIGS absorption layer, an incandescent lamp is adopted to irradiate a surface of a substrate all the time, a change of the intensity of scattered light from the surface of the substrate is detected through a photosensitive sensor, a change of crystal quality of a surface of a CIGS thin film can be easily monitored on line, not limited by the area of the absorption layer, a transition point of a thin film component from poor copper to rich copper can be judged timely and accurately, the component proportion (Cu / (In+Ga)) in a process of deposition of the CIGS absorption layer is indirectly monitored and controlled, the CIGS absorption layer which is uniform and has relatively high crystal quality is prepared, and the performance and rate of finished products of CIGS thin film solar cells are improved. The CIGS absorption layer can be prepared on a rigid or flexible substrate, and the method provided by the invention can be applied to a laboratory deposition process of the CIGS absorption layer, and can also be used for preparation of a large-area CIGS thin film.

Description

technical field [0001] The invention belongs to the technical field of copper indium gallium selenide thin film solar cells, and in particular relates to an online monitoring method for preparing a copper indium gallium selenide absorbing layer. Background technique [0002] copper indium gallium selenide (Cu(In 1-x , Ga x ) Se 2 , hereinafter referred to as CIGS) thin-film solar cells have the advantages of high photoelectric conversion efficiency, good stability, and strong radiation resistance, and are considered to be one of the most promising photovoltaic devices. In 2014, the efficiency of CIGS thin film solar cells with rigid substrates manufactured by the Stuttgart R&D center (wurthsolar) of German Manz company reached 21.7% (the cell area is about 0.5cm 2 ), surpassing the world record for polysilicon cell efficiency for the first time. In addition, the efficiency of CIGS thin-film solar cells prepared on plastic substrates by the Swiss Federal Institute of Tech...

AI Technical Summary

Problems solved by technology

However, the monitoring range of a single temperature sensor is limited, it can only accurately reflect a certain local temperature change, and the position of copper selenide on the film surface is random, for the deposition of large-area CIGS film, it is difficult to monitor the temperature sensor Accurately and timely judge the transition point from copper-poor to copper-rich

It is difficult to obtain CIGS thin films with uniform and high crystalline quality even if the abrupt temperature change point is monitored

The X-ray fluorescence spectrometer installed at the winding end of the substrate is only an auxiliary quantitative detection equipment, which can accurately give the composition ratio and thickness of the film, but has a certain hysteresis, and cannot detect the change of the composition ratio during the film growth process online, and cannot monitor Does the CIGS absorber undergo a suitable Cu-rich growth process?

It is also reported in the literature that atomic absorption spectroscopy is used to detect the composition ratio of the absorbing layer film online. This method can only detect the composition ratio of the film in a small range, and it is also not suitable for large-area film deposition, and the use and maintenance costs of the atomic absorption spectroscopy device are high. Wide application in large-area CIGS film batch production lines is unrealistic

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