Hi Arvind,

in short: in both techniques you apply a voltage pulse to your device (often a schottky-type diode) and observe afterwards how trap states slowly emit charge carriers.

In the conventional DLTS you observe this emission by measuring the transient of the capacitance vs time. This is done by a capacitance bridge normally using a small sine voltage at 1MHz. In this measurement the space charge region is used as a transducer between the trap states and the measurement. This works well for traditinal semiconductors (Si, GaAs etc.) but does not generalize well to other semiconductors (Organic, Nanostructured etc..)

In Q-DLTS you measure the transient of the device current. This is a much more direct way to observe traps, but has restrictions if you want to observe long timescales.

We discuss a part of this topic in the supplementary material of our paper (link attached):

Deep Level Transient Spectroscopy (DLTS) on Colloidal-Synthesized Nanocrystal Solids - D. Bozyigit et al.

What you need experimentally for a QDLTS measurement system is also decribed in the supplementary information. (Although we replaced the Oscilloscope by a digitizer NI-6361).

I hope this helps you,

Deniz

Other useful literature references:

Electrical Characterization of Organic Electronic Materials and Devices - Peter Stallinga

Article Deep Level Transient Spectroscopy (DLTS) on Colloidal-Synthe...

Hi,

I do not know how you can convert it, but may I ask you what type of pump are you using? What is the required vacuum pressure? I am looking to set up a system.

Thanks in advance.

In our lab we are using a Janis ST-500 cryostat and a Pfeiffer HiCube 80 Eco (small turbopump). The base pressure before cooldown is typically 1 to 5e-5mbar. After cooldown at 150K the pressure goes down to

thank you Deniz.

Please refer to section 3.1.2 in DOI: 10.1007/3540095950_9