Hi, I need to calculate the current in a 400nm piece of graphene. Can some one help me please? I found online that graphene has electron mobility of 200,000 cm^2/( V s). My best attempt is as follows. Using the equation vd = uE where E is the magnitude of the electric field applied to a material, vd is the magnitude of the electron drift velocity (in other words, the electron drift speed) caused by the electric field, and µ is the electron mobility (wikipedia). I found that vd= 200,00 cm^2/s. From here I am not sure of I should divide by 400nm to get a speed and then use that to calculate total electrons passing per second to find coulombs. Please help.