I think it depends on applications, i.e.

1 V would be useful for aqueous sensors;

3 V for portable electronics;

5 V for digital circuits;

Higher voltages than 5 V may be useful for evaluation of mobility of the active layer, e.g. to mitigate charge injection problems.

What do you think?

5V is used for digital electronics, normally.

For aqueous sensors, it is 1V.

For digital electronics it may be 5V. Sir in my opinion organic FET or other organic electronic devices is fruitful at low voltage, in case of the sensing lover than the 1V is also applicable. 

High-performance Organic FETs work with low-operating voltages. For such OFETs a low threshold of 0.77 V and a low-operating voltage (0 to 3 V) is compatible with

the voltage level commonly-used in current electronic industry. We can find more details in the paper of L. Shi, et al "High-performance, low-operating voltage, and solution-processable organic field-effect transistor with silk fibroin as the gate dielectric". 

Regards

Laurent Artola

In case of digital u will need 5 V to operate the FET.

While in case of sensors it is almost 1 V required.

Thanks

Muhammad,

Can you explain why 1 V is required for sensors?

I don't understand most of these responses. I also don't understand the question!

A lot depends on the 'threshold voltage' of the device. 

It is assumed that the threshold voltage is close to zero. The operational voltage refers to gate voltage.