Presentation is loading. Please wait.

Presentation is loading. Please wait.

New Sample I-V, PL & PLE Toshiyuki Ihara ’04 07/05.

Similar presentations


Presentation on theme: "New Sample I-V, PL & PLE Toshiyuki Ihara ’04 07/05."— Presentation transcript:

1 New Sample I-V, PL & PLE Toshiyuki Ihara ’04 07/05

2 Sample information n-type-doped single wire 5_7_04.1(accumulation)5_7_04.2 (depletion) #1PerfectI-V, PL & PLE #2Perfect #3Perfect – isolated linespractice #4Poor – lots of lines #5PerfectI-V, PL #1Poor – lots of lines #2Perfect #3PerfectI-V #4Perfect – Scattered lines #5Bad #6Badpractice I measured I-V of sample 5_7_04.1 #1,#5 and 5_7_04.2 #3 PL & PLE spectra of 5_7_04.1 #1are novel data. (I have shown the PL data of sample 5_7_04.1 #5)

3 I-V measurement introduction I applied 4 electrodes to each sample –A,B : Gate –C,D : Earth (stem) I measured I-V between these 4 electrodes at the temperature of 5K and 300K. However, I found that some electrodes don’t work properly because of insulations.

4 I-V measurement Sample 5_7_04.1 #5 (accumulation) 300K5K 300K A-B (gate–gate) C-D (earth–earth) A-C (gate–earth)

5 I-V measurement Sample 5_7_04.1 #1 (accumulation) Small leak current 80nA / 0.8V at 5K 300K5K

6 I-V measurement Sample 5_7_04.2 #3 (depletion) Gate-earth I-V : Ohmic current… –Process failure? –Nature of high-dope sample(accumulation)?? 300K

7 PL & PLE measurement introduction I measured PL scan, wire & arm PL and PLE Vg dependence of sample 5_7_04.1 #1(depletion type) It is hard to measure PLE spectra by previous method ( integral all emission aria) because it is very difficult to decrease the scattered laser. I changed integral aria from all emission to low energy tail.

8 PL scan ~ sample quality 0 - 100μm (1μm step) Vg = 0.25V Laser 10μW stem excitation (1.665eV) Reflection geometry Still some ML fluctuations…

9 Wire PL & PLE Vg dependence Wire normalized PL & PLE spectra Almost same result as before (for ICPS) ① exciton blue shift ② trion doesn’t shift ③ Ex – Ex - increases ④ trion→plasma (0.3V - 0.5V) ⑤ PLE shape at high voltage (0.8V) ※ No irregular PLE absorption peak (arrow) X X-X- FES BOWA ※ This is because the PL integral aria is narrow (low energy tail ) Integral aria

10 Arm PL & PLE Vg dependence Arm well normalized PL & PLE spectra Not the same result as before ① cannot resolve X absorption and X - absorption ② PL peak (unknown origin) ① ② X X-X-


Download ppt "New Sample I-V, PL & PLE Toshiyuki Ihara ’04 07/05."

Similar presentations


Ads by Google