Low resistance indium tin oxide films on large scale glass substrate

學生 :葉榮陞指導老師 :林克默

Introduction Experimental Result and Discussion Summary

OUTLINE

TCO coatings have been widely and intensively studied for many years.

There are two important restrictions for large scale applications, they are substrate size and substrate temperature.

In this paper, we report the result of ITO coating by a plasma deposition technique newly developed for the coating on the large scale glass substrate for architectural applications.

Introduction

The essential feature of the deposition technique used here is low voltage high current electron beam (EB) deposition.

All coatings in this experiment were carried out at the constant discharge current of 250 A.

The maximum glass size was 1.8 m X 3.2 m with thickness of 6-15 mm.

Experimental

A. Deposition rate

The deposition rate was as high as 4000 Ǻ /min with the Ar flow rate of 30 sccm.

Result and Discussion(I)

B. Effects of the substrate temperature

1. Resistivity and haze

As shown in the figure, the haze value of the film has a maximum around the initial substrate temperature of 125°C.

Result and Discussion(II)

B. Effects of the substrate temperature

2. Crystallinity and surface morphology

Film B (haze value of 9.2%) deposited on the substrate preheated at 125°C showed the coexistence of amorphous and crystalline phases, which is clearly demonstrated by the halo pattern around the (222) peak of In2O3 in the XRD chart (Fig. 3).

Result and Discussion(III)

B. Effects of the substrate temperature

2. Crystallinity and surface morphology

Figure 4 shows the STM images and surface profiles of

these films.

Result and Discussion(IV)

B. Effects of the substrate temperature

2. Crystallinity and surface morphology

Figure 5 is a 60° inclined SEM image of the ITO film surface deposited at 100 °C , showing the onset of the recrystallization.

Result and Discussion(V)

C. low resistance ITO coating on large scale Substrate

1.Film structure

The photographs of the cross-sectional SEM image of the film are shown in Fig. 6.

Result and Discussion(VI)

C. low resistance ITO coating on large scale Substrate

2. Optical properties

Figure 7 shows the spectral transmittance and reflectance of the coating.

Result and Discussion(VII)

C. low resistance ITO coating on large scale Substrate

3. Uniformity

The results of the measurements are shown in Fig. 8 as contour plots.

Result and Discussion(VIII)

C. low resistance ITO coating on large scale Substrate

4. Durability

The hardness of the film was greater than that of the glass itself by 68%. The adhesion strength of the film to the substrate was sufficiently good and no failure took place on the tape peel off tests.

Result and Discussion(IX)

A large scale plasma deposition system has been developed to form low resistance ITO films with high deposition rate on architectural size glass substrate. A set of low voltage high current EB sources were used for the deposition.

Summary

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