Charge Carrier Extraction by Linearly Increasing Voltage

Charge Carrier Extraction by Linearly Increasing Voltage (CELIV) is a novel time-resolved method to study the charge carrier transport and recombination in semiconductors with wide range of conductivities.
Generally, the only most important requriement for CELIV measurement is a blocking contact so that no dark injection would be present during carrier extraction.
CELIV allows to measure:
1. Both electron and hole mobilities as a function of time, external electric field, temperature, excitation wavelength.
2. Decay of carrier concentration from which carrier lifetime of recombination constants can be estimated.
3. Sample thickness or dielectric constant as a function of time.
4. Intrinsic film conductivity.
CELIV advantages:
- Materials with a broad range of conductivities can be studied.
- Material conductivity is measured directly from the current transients (unlike from I-V).
- Carrier mobility time-relaxation can be measured directly.
- Dispersive transport up to a certain level is measurable.
CELIV disadvantages:
- In thin films mobility of both electrons and holes immeasurable simply due to too fast extraction time.
- Requires blocking contacts.
- Built-in potential extracts charge carriers.
- Injection might be too high due to offset voltage compensating the built-in potential.

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