I am reading this book:Solid State Electronic Devices by Ben G Streetman and Sanjay Kumar Banerjee. I have some doubts in the article 3.2.2 Effective mass. In this the aythors say that ...
I was reading about concept of effective mass on Wikipedia and came across the line that effective mass of a particle can be negative and even zero. How is this possible?
I have read that holes in semiconductor are nothing but vacancies created by electrons. But how can this vacancy i.e. hole has a mass?