# Introduction to Semiconductors

Sushin Tiwari asked over 1 year ago

Why do holes have effective mass although being vacant energy states ?

Navneet Singh answered 6 months ago

Hi Sushin,

In solid state physics, a particle's effective mass (often denoted {\textstyle m^{*}}) is the mass that it seems to have when responding to forces. Here, although we define and understand holes as vacancies, when they "move" towards the positive terminal under the electrical field, the concept of effective mass is introduced.

Hope this helps.