Együtt-párologtatott négykomponensű félvezető vékonyréteg fotovoltaikus célra = Co-evaporated four-component semiconductor thin films for photovoltaics

A CIGS PV szerkezet kutatasanak celja az egyutt-parologtatasos előallitasnal fellepő folyamatok megismerese; es az n-tipusu puffer-reteg letrehozasa vakuumtechnikailag zart ciklusba rendezhető modon. Utobbit az atomi reteg-levalasztasi technika hazai bevezetesevel oldottuk meg. Kb. 200 ciklusban Zn-es 2 at% Al prekurzor-technikaval Al-mal adalekolt ZnO-retegek uveg hordozon T= 210-220°C-on reprodukalhatoan kialakithatok n=1,2•1021cm-3 adalekkoncentracioval, µ= 0.7 cm2/Vs mozgekonysaggal ill. ρ≈2 mΩcm (1 ill. 7 mΩcm lateralis es normalis) vezetőkepesseggel. A CIGS retegnovesztest un. flash-parologtatasos modszerrel es utolagos szelenizacioval vizsgaltuk. Ampullaban, egyuttes parologtatassal (T=500°C, t=15min) csak kalkopirit osszetevők mutathatok ki, a hőkezeles csak a Ga-tartalmat befolyasolja. Az idealis CuIn0,8Ga0,2Se2 osszetetel 10-15 perces hőkezelessel beallithato a szokasos morfologiaval, amit konformalisan fed be a kb. 40nm ALD pufferreteg . Uvegen, Mo-elektrodra parologtatott (In, Ga) es porlasztott (Cu) femosszetevők retegsorrendjenek szerepe dontő utolagosan szelenizalt retegszerkezeten. Felparologtatott Se-forras hőkezelesevel (valtozo gőznyomason) vakuumban a szelenizacio nem sikeres, de konstans gőznyomason (ampullaban) tokeletes, ha a femretegek sorrendje In, Ga, Cu. | The research on CuInGaSe2 (CIGS) thin film PV structures aimed at understanding of fundamental phenomena at the co-evaporation of the absorber layer; and the development of n-type buffer-layer by an integrable vacuum-method. Latter problem was solved by the adoption of the Atomic Layer Deposition (ALD) technique. In ca. 200 cycles of alternating Zn and ca. 2at% Al precursor pulses Al-doped ZnO layers on glass substrates could be formed reliably at T= 210-220°C with n=1,2•1021cm-3 doping concentration, µ= 0.7 cm2/Vs mobility and ρ≈2 mΩcm (1 vs. 7 mΩcm lateral and normal) resistivity. CIGS layer growth by the "flash-evaporation" method and with the post-selenisation of the metallic precursors was studied. Co-evaporation at T=500°C, t=15min results in solely chalcopyrite components, annealing time affects only the Ga-content in the layer. The composition CuIn0,8Ga0,2Se2 ideal for PV application can be set by an annealing for 10-15 min with the usual morphology, to be covered conformally by the ca. 40nm ALD buffer. The influence of the sequence of evaporated (In, Ga) and sputtered (Cu) metallic components on Mo-coated glass was studied by structural analyses on post-selenized d= 800…1200 nm layers. By the annealing of evaporated Se-source on top in vacuum (i.e. at varying Se vapour pressure) selenization was not successful. At constant vapour pressure (ampoule method) with a metal-layer order of In, Ga, Cu selenization is perfect.