The mechanism for the 1.54 mum luminescence of erbiumdoped porous silicon and the method of attaining a high efficiency.

在1997年的研究中，Er，Yb，Nd和Ho被选为稀土元素，并被掺入到多孔硅（PS）和晶体硅（c-Si）基质中，由于掺Er的PS的4f电子跃迁而产生的1.54 μ m发光显示出约10 nm的宽度。在本研究期间，我们引入了Er掺入后在-1000 ° C下的氢等离子体退火，并获得了由半峰全宽（FWHM）小于1 nm的尖锐峰组成的光谱。我们解释了氢等离子体处理使氧化硅和非晶硅区被刻蚀掉，而剩余的掺铒硅纳米晶出现尖锐的发光峰，这些尖锐的发光峰存在一个小的热猝灭。这是由于硅纳米晶体的带隙增加：（在MRS 1997年秋季会议上提出，并提交给J.Apple.Phys.）我们研究了Yb - 1.0 μ m发光从Yb掺杂PS作为主机PS处理过程的函数。PS的预氧化使Yb的发光强度增加了一个数量级。对PS和Yb发光衰减时间的测量表明，氧钝化PS的悬挂键减少了非辐射复合中心，从而提高了PS到Yb的能量转移效率。（发表于J.Appl.Phys.）我们测量了Nd掺杂的PS的衰减时间，并获得了200-300 μ s的0.93 μ m和1.06 μ m的发光峰的衰减时间。在与阿姆斯特丹FOM研究所的A.Polman博士的合作中，将Ho离子注入到c-Si中，并首次观察到由于4f电子跃迁而引起的-1.2 μ m的发光。

In the 1997 research year, Er, Yb, Nd as well as Ho were chosen as rare earth elements and were incorporated into porous silicon (PS) as well as crystalline silicon (c-Si) hosts.The 1.54 mum luminescence due to the 4f electron transition from Er-dope PS showed formerly a width of about 10nm. In this research period, we introduced a hydrogen plasma annealing at -1000ﾟC after Er incorporation and obtained spectra composed of sharp peaks whose full-width-at-half-maximu (FWHM) is less than 1nm. We explained that silicon oxide and amorphous silicon regions were etched off by the hydrogen plasma treatment and that the remained Er-doped silicon nanocrystals showed sharp peaks.These sharp luminescence peaks exibited a small thermal quenching. This was due to the increased bandgap of silicon nanocrystals : (Presented in the MRS 1997 Fall Meeting, and submitted to J.Apple.Phys.)We studied the Yb - 1.0 mum luminescenece from Yb doped PS as a function of host PS treatment processes. Pre-oxidation of PS resulted in the one-order increase in the Yb luminescence intensty. Measurements of the decay times of PS and Yb luminescence showed that the passivation of the dangling bonds of PS with oxygen reduced the nonradaitive recombination centers, which led to an increse in the enrgy transfer efficiency from PS to Yb. (presented in J.Appl.Phys.)We measured the decay time of Nd doped PS,and obtained the decay times of 200-300 mus for the 0.93 mum and 1.06 mum luminescence peaks. In colaboration with Dr.A.Polman of FOM institue in Amsterdam, Ho ions were inplanted into c-Si, and the luminescence at - 1.2 mum due to the 4f-electron transition was observed for the first time.