What is meant by transition and space charge capacitance of a diode?

space charge region in a diode or say a bjt for better understanding is same as the depletion region,

both transition capacitance and depletion capacitance are the same

c= (epsilon*A)/d ;

where ... c is capacitance

A is area

and d is the depletion width

the other type of capacitance is the diffusion capacitance

c= (T*I)/(n*V)

where ... c is the capacitance

T is transition ti

me

I is the drift current

n is emission coefficient ... its value is 1 for germanium

and V is thermal voltage .. 26mv