Room Temperature CV

Room temperature Capacitance-Voltage Setup is located in 1.820, LASE's group room, on their probe station. 

We are using Hioki 3534-50 LCR Hi-Tester and RS-232C communication protocol. 

(Manuals are here: 3534-50 LCR Hi-Tester and 9593-01 RS-232C Interface) 

Turn on probe station microscope light by pressing the big red power button on the probe station. Place your samples and probes on the contacts to be measured using micromanipulators. They have a little button on the sides to shut off the vacuum momentarily for coarse adjustments of probe locations; otherwise, just use knobs. Probes are not ideal, so be careful to scratch as little of your sample if possible. If the sample is on the LCC, you can use the LCC contacts. 

Note: Hioki cannot supply negative voltages. Therefore, you need to make sure your BNC connections are connected to the correct probes (or make sure probes are in the right bottom vs. top contacts.) When the probe is connected to Lcur and Lpot, it is low, and when it is connected to Hpo and Hcur, it is high, meaning that if you have the low probe connected to the bottom contact and the high probe connected to the top contact, you will be supplying positive voltage across the device. 

You would need your computer with Python installed on it (and serial, time, csv libraries) to operate the setup in an efficient manner. (Though it can be operated manually, too.) The code is attached below. Most basic measurement parameters can be changed there, such as frequency, voltage, etc. 

Plug in the RS-232 USB cable into your computer. Make sure to check which COM# port your computer uses for the Hioki and change the code accordingly. 

Change the code and run it in your favorite manner (either through a command line or an editor).

The data is outputted in a csv format with frequency, voltage, parallel capacitance, parallel resistance, and monitored voltage/current entries. These can also be changed. (You have to change csv entries in two places in the code. Otherwise, you'd get an error.)

cv4_csv.py  - To be updated