Arizona State University, Tempe, AZ 85287, USA.
ACS Nano. 2010 Feb 23;4(2):671-80. doi: 10.1021/nn901699h.
We demonstrated a general methodology of growing spatially composition-controlled alloys by combining spatial source reagent gradient with a temperature gradient. Using this dual gradient method, we achieved for the first time a continuous spatial composition grading of single-crystal quaternary Zn(x)Cd(1-x)S(y)Se(1-y) alloy nanowires over the complete band gap range along the length of a substrate. The band gap grading spans between 3.55 eV (ZnS) and 1.75 eV (CdSe) on a single substrate, with the corresponding light emission over the entire visible spectrum. We also showed that the dual gradient method can be extended to achieve alloy composition control in two spatial dimensions. The unique material platform achieved will open a wide range of applications from color engineered display and lighting, full spectrum solar cells, multispectral detectors, or spectrometer on-a-chip to superbroadly tunable nanolasers. The growth methodology can be extended more generally to other alloy systems.
我们展示了一种通过空间源试剂梯度与温度梯度相结合来生长空间组成可控合金的通用方法。利用这种双梯度方法，我们首次在基底长度上实现了单晶四元 Zn(x)Cd(1-x)S(y)Se(1-y) 合金纳米线在整个能带隙范围内的连续空间组成渐变。带隙渐变范围跨越单个衬底上的 3.55 eV（ZnS）和 1.75 eV（CdSe），相应的发光覆盖整个可见光谱。我们还表明，双梯度方法可以扩展到实现两个空间维度的合金组成控制。所实现的独特材料平台将从彩色工程显示器和照明、全光谱太阳能电池、多光谱探测器或光谱仪到超宽带可调谐纳米激光器等广泛应用中受益。该生长方法可以更广泛地扩展到其他合金体系。
