Nice video, but I think it helps to delve back into history a little. The first transistor I used (circa 1966) was the Mullard OC71. Encased in glass, 'floating' in silicon grease, the transistor had an emitter on one side, a collector on the other, and a 'base' or substrate in the middle. Very much like a triode vacuum tube's cathode, anode and grid. I think it is helpful to think of the function of "holes" and "electrons" while gazing at these old glass transistors. Interestingly, if you removed the black paint off the glass, the transistor became light sensitive, and so the "photo-transistor" was born. Today's CCD and CMOS imagers are millions of times more complex, but the basic function of each transistor is the same: an emitter, a gate (base), and a collector (either of electrons or holes, depending on P or N type design)(MOS designs arrived in the 1970s, different element names, but still the same functional concept).

I have attached images of an OC71 PNP junction transistor from the factory, two with the black paint removed, and Xray through a very similar OC44, and a diagram of the junction elements showing the P-type diffusion regions in the N-type base.