Diffusion anneals were carried out at temperatures ranging from 20 to 270C in evacuated silica ampoules, using diffusion sources of elemental I or CdI2; both under saturated vapor pressure conditions. The concentration profiles were measured by using radio-tracer/sectioning or secondary ion mass spectrometric techniques. It was found that the profiles comprised 4 sections (table 5). A computer analysis which was based upon the sum of 4 complementary error functions gave satisfactory agreement with the data. The fastest diffusing component furnished diffusivity values which agreed with previously published data, but the overall results indicated that I which was diffused into CdTe from the vapor was not suitable as a long-term stable dopant when sharp junctions were required.

E.D.Jones, J.Malzbender, J.B.Mullin, N.Shaw: Journal of Crystal Growth, 1994, 138, 279-84

 

 

Table 5

Diffusivity of I in CdTe

 

Temperature(C)

Source

Sample

Section

Diffusivity(cm2/s)

20

I

bulk

1

3 x 10-17

20

I

bulk

2

1 x 10-16

20

I

bulk

3

2.5 x 10-15

20

I

bulk

4

3 x 10-14

270

CdI2

bulk

1

2 x 10-18

270

CdI2

bulk

2

3 x 10-17

270

CdI2

bulk

3

4 x 10-15

270

CdI2

bulk

4

3 x 10-12

20

CdI2

bulk

1

2 x 10-20

20

CdI2

bulk

2

6 x 10-19

20

CdI2

bulk

3

3 x 10-17

20

CdI2

bulk

4

2 x 10-14

85

CdI2

epitaxial

1

5 x 10-20

85

CdI2

epitaxial

2

4 x 10-18

85

CdI2

epitaxial

3

3 x 10-16

85

CdI2

epitaxial

4

9 x 10-14