Bismuth effects on crystallization of amorphous selenium

Materials

Chemistry

and Physics,

23 (1989)

541-550

541

SHORT COMMUNICATION

BISMUTH --

H.

EFFECTS

ATMANI

and

Laboratoire

ON

C.

CRYSTALLIZATION

OF

AMORPHOUS _

SELENIUM

VALJTIER

d’Etudes

des

Couches

Minces

Amorphes

et

Polycristallines, FacultG

des

Received

Sciences,

BP

January

II,

118,

1989,

76134

Mont-St-Aignan

accepted

february

Cedex

10,

(France).

1989

ABSTRACT BixSe

cal

samples

l-x

terized

by microscopy

reports

of

content.

The

determined.

bismuth

flash

are

chosen

:

that,

effects

on

been

techniques.

opt

This

of

the

the

frequency

at

low

percentag,es,

crystallization

Two

sample

and

of

i-

paper

phenomenon.

ageing

even

charac-

(D.T.A.),

crystallization

energy

show

have

analysis

X-ray on

activation

drastic

method

thermal

obtained

Results

has

the

high-temperature

results parameters

bismuth

by

differential

and

some

experimental

are

deposited

means

and

its

factor

amorphous

sele-

nium.

INTRODIJCTION Among

the

selenium,

materials

bismuth

This

paper

lizat

ion.

thermal X-ray

flash the

with

evaporat

relation

to

PREPARATION The poration

energy

AND

COMPOSITION

BixSel_,(O
0254-OS84/89/$3.50

samples,

The

Bi,Se,_,

of

and

Bi,Se,_,

Se

the

crystal-

techniques

samples

are

and are

high

and

by such

are

the

age

used

tempe-

deposited

crystallization factor

as

determined of

the

in sample.

SAMPLES were

thin

[1,2,3,4]

microscopy

of

THE

amorphous

films

several

bismuth

OF

with

characteristics thin

frequency

mixtures Bi

alloyed

optical

the

percentage

from

the

parameters and

the

method

of

analysis,

Some

ion.

been

interesting

study

diffraction.

activation

have

some the

characterize

differential rature

shows

deals To

which

prepared

powders

;

by this

the

flash

technique

0 Elsevier Sequoia/Printed

evahas

in The Netherlands

542 been

described

nature

of

in

the

a

previous

analysis

paper

[I].

techniques,

Because

several

of

the

samples

destructive

were

prepared

simultaneously. Before

characterization,

checked

by

the

Perkin-Elmer

the

atomic

absorption

device

layers

is

of

the

before

evaporation

composition

(type same

;

the

the

spectrometry

2380).

order

of

The

of

are

was

technique

bismuth

magnitude

results

samples in

content

as

that

given

of of

with

the

10

a

evaporated mixture

% error.

EXPERIMENTAL Characterization Our in

procedure

samples

a

Stone

device

previously copy

were

(type

.

[I,“]

(microscope

technique

characterized LB

Other

type

by

202)

differential

following

the

measurements

Ortholur)

(Guinier-Lenne

were

and

by

chamber)

thermal

a

method

made

analysis

described

by

optical

micros-

high-temperature

X-ray

p].

Results Measurements Two

and

comments

experimental

bismuth

and

Two

parameters

the

age

examples

percentages

of of

of

the

are

the

percentage

of

sample.

thermograms

bismuth

:

considered

are

obtained shown

on

for Fig.

different

ages

l(a,b,c,d,e,)

and

and

Fig.

2(a,b,c,d). The

older

the

sample,

crystallization tioned

peak

for

pure

percentage

of

occurs.

selenium has

the

samples be

at

order

carried

out

samples,

ributed to

obtain

by

optical

ma

[6])

This

phenomenon

such

materials

wing

the

evolution

same

effect

T

=

be

attributed

characterizes and

the

crystal

Figure on

338K

for

to the

was

shows

The

orange

not

the of

in peak

were

skin-like case

for

Se

microclusters. of

involved different

of

BiO.04SeO.96

crystallization

difficulties at

the

sharper

an example

and

presence

difficult the

crystallites

the

The

of

measurements 3(a,b)

the

temperature

sizes.

min.

(it

in

shape

observed

Bi0.01Se0.99 60

samples

peak

[S].

men-

increase

the is

the

been

an

the

informations,some

consequently of

peak

selenium in

microscopy.

at

on

which

has

age,

modifies

sharper

decrease

Bi,Sel_,

fixed

bismuth

pure

at

observation a

respectively

on may

a

same

a

with

further

ntained

observed

samples

to

obtained

photographs

aspect

Indeed,

compared

temperature

Given

of

peak.

Bi,Sel_,

the

The p].

bismuth

crystallization

In

lower

Moreover,addition

shifting.

could

the

moments.

in

follo-

543

Fig.

I.

D.T.A. differently.

1T

thermograms

obtained

on

Bi0.005Se0.99j

obtained

on

Bi,Sel_,.

$=0.2OKls

4.OxBi

1.6% Bi

I 380 Fig.

2.

I

I

1

I

T(K)

420 D.T.A.

Thermograms

samples

aged

Fig.

3.

Photograph obtained a : BC0.01Se0.99

Fig.

3.

Photograph obtained b : Bi0_04Seo,96

(T

by optical microscopy = 338K for 60min).

by opt ical CT = 338K for

microscopy 60 min).

545

To

confirm

this

tallographic the

X-ray behavior

temperature

Bi0.04Se0.96

The

the

to

30°C

sample to

4 illustrates

sample.

patterns

which

confirms

the

croscopy

techniques.

The

explain

230°C)

be

of

The

in

either

by

indexation

are

of

performed

allows

the

with

respect

rate

is

heating

is

decrease

been

followed

X-ray

crystallization

obtained

obtained

have technique

; the

an example

the

results

crystallites

apparatus.

of

(from

Figure

9 xl0 -4Kls.

measurements

phenomenon,

a high-temperature

spectra

sizes

D.T.A.

or

patterns

to

on a

characterized

crystal

on crys-

by

wide

; this by

optical

indicates

mithat

the

hexagonal.

mica

Fig.

4.

X-ray

Dependence Figure

spectra of

5 shows

the

crystallization

for

BiD.015SeD.985

centages.

Tp

beyond

IO4

linked

to

obtained

TP the

on

peak) layers

hours. structural

This

Bi0.04SeD.96

sample

ageing

evolution

decreases

on

of

the

with

age

behavior and

phenomenon relaxation

to

respect

; the with

maximum of T P( ageing of the

temperature

shows of

the

is

reaches the glass

typical a constant importance material.

for

samples other value of

ageing

per-

546 Tp(K 410

405

samples Bio.olsseo.%3ki

400

b(h)

395 10

1

Fig.

5.

iv

Temperature

Tp(K)

versus

10"

the

age

of

10

the

sample.

Tp (K) J/b =0.20

K/s

Age : B months

410.

l 0

0 405. 0

% atBi

,r

,,

Fig.

6.

Temperature

1

2

Tp(K)

versus -~

3

the

percentage

4

of

the

bismuth.

547

Dependence The

of T -----P

temperatures

rep’orted

on

Fig.

temperature tion

at

in

T

be

Determination To

in

+

Fig.

the

determine

Fig.

and

7.

a.

and E

content,

(V

and

E

the

activation

the

Y/T;

versus

and we

versus_

l/Tp

be

of

results

for

the

determined.

corresponding

intercepts The

rate

respectively

Ko, to

I/Tp

energy

heating

the are

III.

In

the

varia-

used

the

equation

and

K,.

lower This

crystallization,

being

factor,

the

the

occurs.

are

cwtallization as

Kissinger

Ko/E)

bismuth

sizes.

such with

The

ln(k

of

peak

of

parameters

slopes

bismuth

parameters

l”y/Ti

obtained II

the

crystallite

allows

7(a,b,c), The

I,

to

frequency

samples.

percentages

crystallization

the

constant) and

different

higher

linked

L7].

-E/kTp

Boltzmann energy

content --.

associated

method =

l”Y/Tf,

for

the

the

factor,

Kissinger

Tp The

of

determine

frequency

bismuth

which

may

P

6.

on

Bi0.005Se0.995.

straight reported

and act

k ivat

We

have

to

different

ion

plotted

1 ines ion

the

Tables

548

1 r03(K-‘1 TP 2’s

Fig.

7.

Ah

b.

InY/Tb

versus

I/Tp

for

Bi0.0lSe0.99.

Y

TP2

l

-13-

s6oh

*fresh

samples

-14. 1.5 Bi

-15,

2.50

2.55

2.60

1 103(K-‘1

TP Fig.

7.

c.

ln’Y/Ti

versus

I/T&?

FoR

Bio.015Se0.985.

*

549

Fig.

8.

In’? /Ti

We have show

the

versus

heating

rate

9.10-4K.s-’

heating

rate

of

Table

I.

X-flay

(D.T.A.

of

sample

p]

that

to

D.T.A.

to

respect 360h

1.o

Bio.0iSeo.99

I .04

1.01 1.03

Values

of

K,(s-‘)

Fresh 5.21~10”

Bio.01Se0.99

9.5

Table

III.

Values of

of

E(eV)

Bi0.005Se0.995

I .04 s-

’)

range

I

.4x

1010

obtained

ageing

(Fig.

8)

to

of

BiSe

on

samples.

2 160h

4320h

I .04

1.04

I .07

1.09

ageing

of

BiSe

samples.

2 160h

4320h

11.36x10”

1.5x10”

1.4~10’~

5.08x1012

2.93~10’~

I .84xlOlO

with

Bi0.01Se0.99 I .09 2.93~10’~

of

uppermost

360h

xl09

and Ko(s-‘)

large

respect

to

the

bismuth.

fiV) Ko(

respect

samples

Bio.005Se0.995

percentage

-with

techniques

X-ray

the

hypothesis.

samples

II.

combined)

(the

curve

this

with

and

over

Bi0.005Se0.995

Table

techniques

3.10-1K.s-’

linear

confirms

Fresh

X-ray

crystallization

; the

E(eV)

of

and

(X-ray)

D.T.A.)

Values

0

previously

mechanism

a BiO.04SeO.96

DTA

l/Tp

reported same

0

Bi0.015Se0.985 ___I. 17 1.53x1012

Bi0.04Se0.96

I .25 7.2~101~

550 CONCLUSION The with

age

sample

the

percentage it

already [9]

who

bismuth.

is

not

E=l.

using technique,

BiC_01SeC_99

mixtures

be

E for

1.35

results in

good The

Taking

may

be

effects

on

compare

Fleury

[IO] on

layers

deposited

account

results

those

of

the

using

those

for Thornburg

and

found

our

errors,

mentioned

to

be

above.

percentages,

of

[II] E to

factors,

low

properties

by

conductivity

eV

experimental

at

et -

prepared the

E=1.64

authors

with

Miranda

; whereas,

even

physical

with mention

seperately

the

bismuth,

with

experimental

experimental the

associated

significant

samples ;

gives

within

that

to

glass

the

Ko

slightly more

the

BiD.C5SeC.g5 technique

is

different

for

D.S.C.

deposited

E and

the

18 eV

with show

of

interesting

into

agreement,

K,

to

considered,

results

drastic

Because

on

increase

E and

seems

Bi-Se

eV.

values of

it

the

measurements

determined

the

effect

easy

But

found and

little

increase

of

published.

quenching

has

since

However,

conditions,

g

the

crystallization,

ageing. the

of

has

selenium.

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Atmani

2

H.

Atmani,

3

J.M.

I

-77

and

Mater.

Saiter, (1985)

C.

Th.

H.

Atmani,

Thesis -__

5

.I.

Grenet,

Thesis,

6

H.

Atmani,

P.

7

H.E.

8

H.

Mater.

Chem.

Chem.

Phys.,

Derrey

and

19 C.

Phys.,

(1988)

fi

(1987)

129.

255.

Vautier,

J.

Non-Cryst.

Sol.,

1169.

4

(1983)

Vautier,

(1988),

Rouen.

(1983),

Michon

and

Rouen. C.

Vautier,

Phys.Stat.Sol.

(a),

75

K5. J.Res.Nat.Bur.Stand.,

Kissinger, Atmani,

Coquerel

G.

and

-57

C.

Vautier,

A.

Conde

(1956)

Thin

217.

Sol.

Films

(to

be

published). 9

H.

Miranda,

Phys.,

13

IO

G.

Fleury,

11

D.

Thornburg

F.L. (1982) Thesis, and

Cumbrera,

and

R.

Marques,

Portugal

53. (1982), R.I.

Rouen.

Johnson,

Thin

Sol.Films,

31

(1977)

107.