The III–V Alloy p–n Diode Laser and LED Ultimate Lamp

In this paper, an account is presented of the semiconductor, because of the energy gap bipolar with electron (e) and hole (h) conductivity, becoming ingeniously with little or no technology (Bardeen and Brattain, Dec. 1947) the transistor, a triode (at first just a germanium “base” crystal and a point contact “emitter” and “collector”), a low impedance “emitter” minority carrier input (IE) into a (the) vital central “base” active region, the base supporting along with essential recombination current I_B (I_B > 0) carrier transport to a higher impedance “collector” output I_C ( I_E+I_B+I_C=0, I_C/I_E=α ~ 0.9), hence gain, thus revealing at last that a current (I_B) can increase the electron-hole (e-h) population, and as a further consequence, yield band-to-band (k_e=k_h) excess carrier recombination radiation (light). The transistor established (1947) a basis for the study of the light-emitting diode (LED). The path to an “ultimate lamp,” the p-n diode laser and LED, is described from semiconductor, to energy gap, e-h bipolarity, transistor, the p-n transition, excess carriers, e-h recombination, direct gap (k_e=k_h) crystal, autocatalytic e-h/photon interaction, spectral narrowing, stimulated recombination (laser), need for resonator (cavity Q, how?), direct-gap (k_e=k_h) III-V alloy, visible spectrum III-V alloy, III-V alloy gap change (ΔE_g), quantum-well (QW) e-h recombination, stimulated emission solving the problem of photon extraction ( → 100% quantum efficiency), the p-n diode “ultimate lamp,” return to the 1947 triode, to the transistor, and the base importance informing the realization of a QW-base transistor laser.