n+-Si在HF水溶液中经光电化学刻蚀形成的微米级多孔硅(PS)具有较好的电致发光(EL)性能,其发光光谱的波长范围约在500~800nm之间,阴极EL的波长和强度均随调制电位可逆变化;在酸性溶液中,发光强度较大,光淬灭过程也较中性溶液为慢.与n--Si的结果类似,PS的制备电位也决定性地影响着EL的强度.光淬灭前的伏安行为表明,除S2O2-3和H+还原外,可能还涉及PS表面化合物的转化.对能带图进行了讨论.
Porous silicon with micrometer size pores, which is made on n + Si by photoelectrochemically etched, has electroluminescent property. Each monochromic intensity and wavelength range of luminescent spectra depend on polarized potential. The intersity and the stability of cathodic electroluminescence is high than those of anodic one. Voltammetric behavior before quenching indicated that the electrochemical reactions of some surface species are involved in except the reduction of S 2O 2- 8, which leads to radiative recombination. The energy band diagram based on n + Si (E g=1.1 eV)/PS(E g=1.8 eV) junction is proposed.
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