What are the differences between TEM and SEM (transmission vs scanning electron microscopy?

Basis of differentiation

TEM

SEM

Definition

TEM is a method in which beams of electrons are passed through a sample to generate an image

SEM uses electrons which are reflected off the surfaces of samples to produce an image

Depth of field

Moderate

High

Magnification

5,000,000 X

100,000 X

Image produced

Generates a 2D black and white image

Generates a 3D black and white image

Resolution

High resolution

Comparatively lower resolution than TEM

Sample preparation

Does not have any strict requirements for sample preparation and requires little effort since samples are placed directly on an aluminum stub

Samples must be very thin, and are typically below 100 nm and is a complex process which requires training and experience; samples are placed on copper grids