Ag掺杂p型ZnO薄膜及其同质结的光电性质

Electrical and Optical Properties of Ag Doped p-type ZnO Films and Its Homojunctions Properties

采用磁控溅射技术在Si基片上生长了Ag掺杂的ZnO薄膜,XRD测试表明所得薄膜结晶性质良好,未出现Ag的分相。未掺杂和Ag掺杂氧化锌薄膜的低温(10K)光致发光(PL)谱显示:Ag的掺入使得中性施主束缚激子发射(D0X)显著减弱,并且在3.315eV处观测到了与Ag有关的施主-受主对(DAP)发射,受主缺陷的形成归因于掺入的Ag替位Zn。计算得到受主能级离价带顶约110meV。霍尔效应测得电阻率约0.1Ω.cm,迁移率约36cm2/V.s,空穴浓度约1.7×1018cm-3。在此基础上制备了ZnO∶Ag/ZnO的同质结,I-V测试显示了明显的整流特性,且反向漏电流很小。所有结果表明Ag掺杂的氧化锌薄膜已经转化为p型。

Ag doped ZnO films have been fabricated on single-crystal Si （100） substrates by magnetron sputtering. XRD measurements show that the ZnO： Ag films have high crystallization quality without new phase related to Ag appearing. Doping with Ag can clearly decreases the neutral donor bound exciton emission showed by the low temperature （10 K） photoluminescence spectra; a donor-acceptor pair emission has been observed at 3. 315 eV which is attributed to the formation of acceptor defect （Ag substitutes Zn）. The level of AgZn acceptor is estimated to be about 110 meV above valence-band maximum. Hall measurements show that Ag doped ZnO films are p-type conductivity with the resistivity about 0. 1 Ω·cm, hole concentration about 1.7 × 10^18 cm^-3, and mobility about 36 cm^2/V·s . The two-layer structured ZnO p-n homojunctions have been prepared on Si（100） substrates by depositing Ag doped p-type ZnO film on intrinsic n-type ZnO film using magnetron sputtering. The current-voltage （I-V） characteristics derived from the intrinsic ZnO/Ag doped ZnO two-layer structure clearly show the rectifying characteristics of typical p-n junctions.