If you are interested in downloading the PDF version of "Basic Electronics" by BL Theraja, you can search for it online. However, be sure to only download from reputable sources to avoid any copyright or malware issues.
This is the meat of the book. Theraja explains intrinsic and extrinsic semiconductors (P-type and N-type) with crystal-clear diagrams. He covers the PN junction, barrier voltage, and depletion region in a way that even a high school student can grasp. Basic Electronics By Bl Theraja PDF
If you are looking for alternative resources to learn electronics, here are some options: If you are interested in downloading the PDF