Depletion Sample I-V, PL & PLEDepletion Sample I-V, PL & PLE

Toshiyuki Ihara

’04 07/13

Sample informationSample information• n-type-doped single wire

5_7_04.1(accumulation) 5_7_04.2 (depletion)

#1 Perfect I-V, PL & PLE

#2 Perfect

#3 Perfect – isolated lines practice

#4 Poor – lots of lines

#5 Perfect I-V, PL

#1 Poor – lots of lines

#2 Perfect

#3 Perfect I-V,PL&PLE

#4 Perfect – Scattered lines

#5 Bad

#6 Bad practice

I measured I-V, PL & PLE of sample 5_7_04.2 #3 depletion sample

Red : new

I-V measurementI-V measurement• Sample 5_7_04.2 #3 (depletion)• Gate-earth I-V• No leak current

between ｰ 0.6~0.3

though I observed

ohmic I-V at 300K

I- V ( gate- earth )

- 4.00E- 07

- 3.00E- 07

- 2.00E- 07

- 1.00E- 07

0.00E+00

1.00E- 07

2.00E- 07

- 1 - 0.5 0 0.5 1

gate voltage (V)

curr

ent

(A)

5K

gate - earth I- V

- 1.00E- 05

- 8.00E- 06

- 6.00E- 06

- 4.00E- 06

- 2.00E- 06

0.00E+00

2.00E- 06

4.00E- 06

6.00E- 06

8.00E- 06

- 0.1 - 0.05 0 0.05 0.1

gate voltage (V)

curr

ent

(A) A- C

A- DB- C

B- D

300K

Wire PL Vg dependenceWire PL Vg dependenceWire PL spectra Vg depen

dence between-0.8V~0.2V

Laser 1μWstem excitation(1.665eV)Reflection geometry

Almost same result as before

60

50

40

30

20

10

0

x103

1.6001.5901.5801.5701.560

a040712006accumulate n- type doped QWR 5-7-04.2 #3 perfect center + 2mt = 10 sT = 3.515 KV = (-0.8) - (0.2)V0.05V steplaser 751nmomec -800NDex 1/ 100, 1/ 1000 (...10W ?)

armwire

X

X-

plasma-0.8 ~ -0.7 Exciton

-0.7 ~ -0.5 Trion

-0.5 ~ 0.1 Plasma

PL scan PL scan ～ ～ sample qualitysample quality0 - 50μm

(1μm step)

Vg : -0.3V or

-0.65V

Laser 1μW

stem excitation

(1.665eV)

Reflection geometry

ML fluctuations or electron density fluctuations !?

50

40

30

20

10

0

x103

1.6001.5901.5801.5701.560

a040712003depletion n- type doped QWR 5-7-04.2 #3 perfect 50m scan1m step (0 - 50m)t = 5 sT = 3.535 KV = -0.3Vlaser 745nmomec -800NDex 1/ 100, 1/ 1000 (...10W ?)

50

40

30

20

10

0

x103

1.6001.5901.5801.5701.560

a040712001depletion n- type doped QWR 5-7-04.2 #3 perfect 50m scan1m step (50 - 100m)t = 5 sT = 3.542 KV = -0.65Vlaser 745nmomec -800NDex 1/ 100, 1/ 1000 (...10W ?)

-0.65V-0.3Varmwire wirearm

Wire PL & PLE Vg dependenceWire PL & PLE Vg dependenceWire normalized PL & PLE spect

ra

Laser / detection : perpendicular

polarization

Excitation : to wire⊥Detection : // to wire

Almost same result as before

PL & PLE of wire

1.565 1.57 1.575 1.58 1.585 1.59

photon energy (eV)

arbi

trar

y un

its.

trion

plasma

laser