多壁碳纳米管阵列场发射研究

A study of field emission of an array of multi-walled carbon nanotubes

研究了Ar离子束轰击及温度对多壁碳纳米管阵列场发射性能的影响 .经Ar离子轰击 35min后 ,发现阵列顶端的Fe催化剂颗粒明显减少 ,弯曲的顶部被轰击掉 ,使碳纳米管的场发射电流明显减小而场发射像无明显改变 .温度的增加引起碳纳米管的场发射电流也随之增加 .还研究了在透明阳极技术中涂在阳极的荧光粉对场发射电流的影响 .对同一碳纳米管阵列样品 ,发现涂有荧光粉的透明阳极使测量到的场发射电流大幅度减小 ,只是未涂荧光粉阳极电流的 1 30左右 .直接用二氧化锡导电膜作阳极时 ,测得样品的开启场强为 1 0V μm .沉积了荧光粉的二氧化锡导电膜作阳极时 ,开启场强变为 2 0V μm .

Arrays of multi-walled carbon nanotube (MWCNT) were bombarded with argon ions and studied with transmission electron microscopy and x-ray photoelectron spectroscopy. Our preliminary results show that after 35?min ion bombardment,most of the MWCNT curls and the iron catalyst particles residing at the top end of the tube were knocked out. Although no obvious change in its emission images is observed,its field emission current considerably decreases. During spontaneous cooling down from an elevated temperature (480℃),its emission current decreases sharply. Interesting finding is that the coating of phosphor powder on the tin-oxide-coated glass anode significantly affects the emission current measurement. For example,the phosphor coating reduces the measured current by over 30?times and increases the turn-on field from 1 0 to 2 0?V/μm.