Документ взят из кэша поисковой машины. Адрес оригинального документа : http://genphys.phys.msu.su/rus/school/Khokhlov.pdf Дата изменения: Mon Nov 1 03:26:07 2010 Дата индексирования: Mon Oct 1 22:02:34 2012 Кодировка: Поисковые слова: m 2

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..

. ..




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( ), ( ) :



(, ) ( )









- ()









,




, ,




,



Background Photon Noise NEP (W/Hz )
1/2

Planck HFI

10

-17

106 105

Background photon arrival rate (1/s)

10-

18

104 103

10-

19

102 101

10-

20

100 1 10

Frequency (THz)


""
12- , 10 K - 2017-2018



(µm)=3000/T(K) : T=6000 K, =500 nm : T=300 K, =10 µm : T=10 K, =300 µm =1 THz ­ !



(TES ­ Transition Edge Sensors) (BIB - Blocked Impurity Band detectors) (KID - Kinetic Inductance Detectors)


State of the art bolometers (Transition Edge Sensor)
0 .2

10
R() 0 .1

C C C C

h h h h

i i i i

p p p p

31 31 31 31

-1 -1 -2 -1

6 3 1 0

13

0 .0

16

0 .1 3

0 .1 4
T (K)

0 .1 5

0 .1 6

21

Optical NEP for Single pixel: ~1x10-18W1/2/Hz by Cardiff /SRON At 45 µm


Ge(Ga) blocked impurity band detectors
h

Blocked Impurity Band BIB structures based on doped Si and Ge The highest red cut-off wavelength: uniaxially stressed Ge(Ga) = 220 µm
Heavily doped Ge
A

Undoped Ge

Problem: the highest NEP achieved so far 10-16 W Hz-1/2 at T well below 4.2 K


Principle of Kinetic Inductance Detector
(Courtesy of A.Baryshev) Pair breaking detector Superconductor ~ LKIN at T S
S21 [dB]

Antenna

1

2

CPW ј Resonator L= 5 mm @ 6 GHz

21

Im
Im R Re

R Re

Al ground plane 100 µm



CPW Through line

f
f
F [Ghz]

F0

F0

F

1

Coupler substrate Central conductor Readout signal ~GHz

2


KID arrays for SPICA
Dark NEP = 10-18 W Hz-1 Resonances @ F0 F0 set by geometry (length)
/2
no light LED on

-15

-20

S21 [dB]

-25

-30

-35 4.056 4.058 4.060 4.062 4.064 4.066 4.068

F [GHz]


( )
< 150 K NEP (?) (?)



( ) ­ : , : ,








PbTe: : 1. Eg = 190 meV T = 0 K L- 2. 103. 3. m 10-2 me.


Pb1-xSnxTe
200 100 0 -100 E, meV Ec

0

0.1

0.2

0.3

0 .4

x

Ev : 10-3. : n,p 1018-1019 -3


,
.

n
7 10 c m
18 -3

NI p
PbTe(In), NIn > Ni

n



1. ( ). EIn EF . EF ~ 70 < 0.1 ( 1017 -2) 103-104

2.

3.


­ PbTe(In)


Pb1-xSnxTe(In) .
EIn

200 150 100 50 0 0,0 -50 -100

E, meV EF
n-type metal

Ec

0,1

0,2

0,3 p-type metal

0,4 x

Ev

semiinsulating state



10 10 10 10 10 10 10 10
5

R, Ohm

2 3

4

3

2

2' 3' 1 4 1' 4'
0 5 10 15 20 25

1

0

-1

-2

100/T, K

-1

, (1-4) (1'-4') x = 0.22 (1, 1'), 0.25 (2, 2'), 0.27 (3, 3') 0.29 (4, 4')



> 10 s
4

Persistent photoconductor

Ordinary photoconductor
radiation on radiation off

t

­ DX-







e e -

neutr.
In3+

2In2+In i

3+ donor

+ In

+ accept. 1) 1)

In2+

In3+

In+
e -

on(left)

= (1) + (

i
e -

on(right)

= (2) + (

In2+

In3+

In3+

In3+

(2) = (1) - U U>0 "Negative-U" : U<0


()


Te

Te In
3+

1

Te
-e

Te In
2+

Te
-e -e

Te In
+

2

Te

Te

Te

Te

Te

Te



Te h
e

Te

In

Te

Te



Etot = Eel + Elat = = (Ei-)n +2/20 (n = 0,1,2) ­
,



E2 ­ ; E1 ­


«»
> 10 s
4

Persistent photoconductor

-




Ordinary photoconductor
radiation on radiation off

t



1. : 25 ­ . 2. -: f = 250 , P = 0.9 , t = 10 102 -.


-

100!




I1 < I2< I3 I2 I3

I1

t quenching pulses


Pb1-xSnxTe(In)
, , . 4.2 K; 18 ( ); 3 ; 300*200 ; > 107 A/; < 10-16 ( 10-7 A).



Pb1-xSnxTe(In) ? Pb1-xSnxTe(In)?



1 ­ 2 ­ 3 ­ 4 ­ 5 ­ 6 ­ 7 ­ 8 ­

8 7 5 T = 4.2 K 4 3 2 1 T = 77 K T = 300 K 6


Si(Sb) Ge(Ga) ()
amplifier overload
2,0x10
-2

= 14 ; state of the art Si(Sb) BIB
Pb1-xSnxTe(In) : 40 ( )

1,5x10

-2

I, µA

300

1,0x10

-2

5,0x10

-3

77 0,0 -0,5 0,0 0,5 1,0 1,5 2,0 2,5

V, V


176 241
6,0x10 5,0x10
-2

-2

176 µm
241 µm

176 241 = 241 , red = 220 Ge(Ga)

Current, µA

4,0x10 3,0x10 2,0x10 1,0x10

-2

-2

-2

-2

0,0 0 200 400 600 800

Time, s




, , . 4.2 K; 350 µm ( , Q=4); 1 Hz; 300*200 µm; NEP ~ 10-13 W/Hz1/2 ( 10-6 A).



, , . 4.2 K; 350 µm ( , Q=4); 100 Hz; 300*200 µm; NEP ~ 3*10-17 W/Hz1/2



, , . 1.57 K; 350 µm ( , Q=4); 100 Hz; 300*200 µm; NEP ~ 5*10-19 W/Hz
1/ 2

!!!


PbSnTe(In)
: 90, 148, 280, 4 9 6 µm : 100 ns : 30 kW : 4.2 ­ 300 K



10 10 10
, Ohm cm
6

10
Pb0.75Sn0.25Te(In)

17

5

10 10 10 10 10 10

16

10

5

4

15

n, c m

-3

10 10 10 10 10

3

14

µ , cm2/ V s

2

13

10

4

1

12

0

11

10

3

-1

0

2

4

6
100/T, K
-1

8

10

12

10

10

0

50

100
T, K

150

200

250







1.4 1.2 1.0 0.8
2

= 280 µm
RL RS h RL >> RS

4.2 K

/*10

0.6 0.4 0.2 0.0 -0.2 -0.4 0 1 2 3 4 5 6
25 K
shape of the laser pulse (arb.un.)

t (µs)




: , : ,



6 5 4 3

90µm

N=8.7 10

-24

c

-1

280µm
2 1

148µm 496µm

0 0 20 40 60 80
-1

100

120

496 , , ­ 220 Ge(Ga)

/0*10

2

(cm )

=0!



.



: ­
: , .. T




n m , T/nm





T nm

n m


«»
h

.
radiation "spot"

photodetector

< 100



10

1
8
0.15 mm
0.07 mm

10 , Ohm .

-1

6

1 1

4

4

1
2

2

3

2
0 0 20

2,3
40 60 80

3
100 120 140

t, s



A

6

5

1

2 3 41

1 ­ 2 ­ Pb1-xSnxTe(In) 3 ­ BaF2 4 ­ 5 ­ 6 ­



Pb1-xSnxTe(In) , : , - 102 «»