Time-Resolved Photocurrent Set-Up


Already today's technologies heavily rely on materials with unique optoelectronic properties. As these materials will only continue gaining importance for future technologies, active research in advanced materials with tailored optoelectronics is indispensable.

The Lake Shore Cryotronics CRX-6.5K Probe Station is the core of our setup enabling time-resolved photocurrent investigations. This way, measurements may be conducted at temperatures between 8.5K and 350K, either under vacuum or in an inert gas atmosphere. To investigate optoelectronic properties, various laser solutions are available. Steady-state photocurrents can be studied using the CW-mode (continuous wave mode) of a 405nm, 636nm, 780nm, or 847nm laser. The utilization of fast on/off switchable lasers furthermore allows for time-resolved photocurrent investigations. Two options, a 635nm and a 1310nm laser are available. These enable photocurrents based on short rectangular pulses. Alternatively, picosecond pulsed laser diodes with 635nm and 780nm may be used. Impulse responses of materials of interest may thus easily be analyzed. This extensive collection of laser diodes allows for analyses ranging from microsecond photocurrents all the way down to short impulse responses lasting merely nanoseconds. Thus, a multitude of possible optoelectronic investigations on diverse materials is reached. As a result, a wide range of time-resolved photocurrents stretching across multiple orders of magnitude can be achieved.

A Lock-In amplifier with Boxcar Averager function (UHFLI, by Zurich Instruments) completes the Probe Station setup. Both, a trans-impedance amplifier (1GHz High Speed Amplifier HSA-Y-1-60, by FEMTO) and two source meters (2634B & 2636B SYSTEM Source Meter, by Keithley), are readily available to be connected to the setup, too. The highest obtainable resolution is 600MHz.

In summary, this setup allows for an easy, broad, and in-depth investigation of important optoelectronic properties of materials that could be used in components of tomorrow's electronic devices.