Preparation chamber 1.Chamber status 2.Preparation methods 3.Results: photocurrent, stoichoimetric control 4.Next step

1. Chamber status  Verdampfer  Blendenmodul  Laser  Control system test  Thickness monitor  Cathode heating  High voltage  Shutter  Cathode plug

2.Methods Cu-sampleSi-waferCu-cathode standard712 sandwich001 co-evaporation010

3. Results Vacuum in the experiment # Photocurrent # Vacuum is not good enough

3. Results Stoichiometric control: Cs/Te ~ 2 NrSub. Te thickness Cs thickness Cs/Te PIXE RBS # Cu10 nm20 nm # Cu10 nm68 nm\1.9 # Si10 nm70 nm1.6\ # Co-evap. Si10 nm46 nm0.8 It is hard to control.

Stoichiometric rate measure (example: # CsTe on Cu) 1. PIXE: Cs/Te=0.55 (calculated by GUPIX, Dr. Grambole) 2. RBS: Cs/Te=0.44 (calculated by XRUMP, Hr. Zhou)

 photocurrent measurement  Photocurrent pulse

4.Next step 1.Chamber cleaning ( mbar) 2.Mo cathode polishing (0.1µm) 3.Clean-room rebuilding Homepage: Logbuch:

NrsubstratumMethodTeCsCs/TePhotocurr.Vacuumcomment nm mbar # Custandard First test # Custandard No HV #03-17Custandard *10 -7 No HV # Custandard µA4.3*10 -7 First photocurrent # Custandard µA3.8*10 -7 QE scan inhomogeneous Improve sources, polish Cu samples, increase high voltage -6 unpolished -6 # Sistandard \2.5*10 -6 # SiCo-evap \ First test on co-evaporation -6

Thickness Quartz thickness monitor STM-1

Co-evaporation #

RBS for thickness and atom rate