It's called this just because it's an electron that results when an electron absorbs a photon's worth of energy, so thus it's a photoelectron.

之所以这样称呼是因为,当一个电子吸收,一个光子的能量的结果，因此它是一个光电子。

麻省理工公开课 - 化学原理课程节选

And if we talk about electrons or photoelectrons, again we can describe it in terms of energy, we can talk about velocity, and from there, of course, you can figure out the energy from 1/2 m v squared, and actually we can also describe the electron in terms of wavelength.

如果我们谈论电子或者光电子，我们又可以从能量的角度来描述它，我们可讨论速率，从那里，当然，你可以计算1/2，m，v2得出能量值，而且事实上我们也可以,从波长的角度来描述电子。

麻省理工公开课 - 化学原理课程节选