60w Led street light solar knowledge:

In a solar cell, a trough of a standing wave (a portion having a high electron density) falls on an atomic position, and some falls between atoms. When the nucleus does not have a positive charge, the two standing waves have the same energy. When the nucleus is positively charged, the trough of the standing wave is present on the atom, but the energy between the atoms is lower than that of the atom, so the band gap becomes larger. The energy band diagram obtained by taking the wave number on the abscissa is different from that of the free electron, and is a multi-valued function of the wave number. Moreover, even if only the unit character a*=2a of the reciprocal character is shifted along the wave axis, the dispersion relation is the same, and therefore only the interval of the minimum unit [-a*2, a*2] is shown. Replacing =a*2 with 2x/=a, with actual space, corresponds to a=2, meaning that the length of the half-wavelength is equal to the character interval.