Passivation of n- and p-Type Silicon Surfaces With Spray-Coated Sol-Gel Silicon Oxide Thin Film

摘要

Thermally grown SiO₂ is widely used for silicon surface passivation in solar cells and other applications due to excellent interfacial properties. SiO₂ films with thickness in the range of 17 nm deposited by industrially viable spray-coating technique on both n- and p-type silicon are reported. Low values of interface state density of ${1.4}imes {10}^{{10}}$ cm $^{oldsymbol -{2}}$ eV $^{oldsymbol -{1}}$ on n-type and ${2.0}imes {10}^{{10}}$ cm $^{oldsymbol -{2}}$ eV $^{oldsymbol -{1}}$ on p-type were achieved. Fixed oxide charges in the range of 7.1– ${9.4}imes {10} ^{{11}}$ cm $^{oldsymbol -{2}}$ and 3.9– ${6.5}imes {10} ^{{11}}$ cm $^{oldsymbol -{2}}$ on n- and p-type, respectively, are obtained. Excellent passivation results in the effective surface recombination velocity of 0.97 cms $^{oldsymbol -{1}}$ and 8.07 cms $^{oldsymbol -{1}}$ at minority carrier concentration of $10^{{15}}$ cm $^{oldsymbol -{3}}$ on n- and p-type Czochralski silicon, respectively, without the use of capping layer. SiO₂ film exhibits dielectric breakdown field strength of 4.3 MVcm $^{oldsymbol -{1}}$ and 5.6 MVcm $^{oldsymbol -{1}}$ and leakage current density of ${2.2}imes 10 ^{oldsymbol -{8}}$ Acm $^{oldsymbol -{2}}$ and ${1.1}imes {10} ^{oldsymbol -{8}}$ Acm $^{oldsymbol -{2}}$ at 1 MVcm