光(guang)(guang)伏發電(dian)(dian)的(de)(de)(de)(de)主要原(yuan)理(li)是半(ban)(ban)導(dao)體(ti)的(de)(de)(de)(de)光(guang)(guang)電(dian)(dian)效(xiao)應。當(dang)光(guang)(guang)子(zi)(zi)(zi)(zi)撞擊金(jin)(jin)屬時(shi)(shi),其(qi)能量可以被金(jin)(jin)屬中的(de)(de)(de)(de)一(yi)個(ge)電(dian)(dian)子(zi)(zi)(zi)(zi)完全吸(xi)收。電(dian)(dian)子(zi)(zi)(zi)(zi)吸(xi)收的(de)(de)(de)(de)能量大到足以克服金(jin)(jin)屬原(yuan)子(zi)(zi)(zi)(zi)內部的(de)(de)(de)(de)庫(ku)侖力做(zuo)功(gong)并從金(jin)(jin)屬表面(mian)(mian)逃逸(yi),成(cheng)為光(guang)(guang)電(dian)(dian)子(zi)(zi)(zi)(zi)。硅(gui)有四(si)個(ge)外(wai)(wai)層(ceng)電(dian)(dian)子(zi)(zi)(zi)(zi)。如果純(chun)(chun)硅(gui)摻雜有五個(ge)外(wai)(wai)層(ceng)電(dian)(dian)子(zi)(zi)(zi)(zi)的(de)(de)(de)(de)原(yuan)子(zi)(zi)(zi)(zi),比如磷原(yuan)子(zi)(zi)(zi)(zi),就(jiu)會變成(cheng)N型(xing)半(ban)(ban)導(dao)體(ti)。如果純(chun)(chun)硅(gui)摻雜有三(san)個(ge)外(wai)(wai)層(ceng)電(dian)(dian)子(zi)(zi)(zi)(zi)的(de)(de)(de)(de)原(yuan)子(zi)(zi)(zi)(zi),例如硼原(yuan)子(zi)(zi)(zi)(zi),就(jiu)形(xing)成(cheng)了P型(xing)半(ban)(ban)導(dao)體(ti)。P型(xing)和N型(xing)結(jie)合在一(yi)起,接(jie)觸(chu)面(mian)(mian)就(jiu)會形(xing)成(cheng)電(dian)(dian)位(wei)差,成(cheng)為太陽能電(dian)(dian)池。當(dang)太陽光(guang)(guang)照射到pn結(jie)上時(shi)(shi),電(dian)(dian)流(liu)從P型(xing)側流(liu)向N型(xing)側,形(xing)成(cheng)電(dian)(dian)流(liu)。