The fabrication of colloidal semiconductor nanocrystals has received great attention during the last decade and their application has now reached a level where they are expected to play a critical role in a variety of emerging areas, such as bioimaging and third-generation solar cells. [1,2] Three-dimensional quantum dots have been studied extensively, [3] and the development of nanocrystals with two-dimensional confinement character, such as nanorods, tipped-nanorods, nano-dumbbells, and hyper-branched nanorods, which offer better flexibility in design and applications, is receiving increasing attention. [4,5] In recent years, new types of heterostructured nanocrystals made of two or more different components have created strong interest for "band engineering"-related properties.[6] Up to now, however, only a few heterostructured nanocrystals with twodimensional confinement character, such as cadmium-selenium/cadmium-tellurium, cadmium-selenium/cadmium-sulfur, and zinc-selenium/cadmium-sulfur nanorods, have been developed, and only a few semiconductors such as cadmium-selenium and zinc-selenium have been used as seed for the synthesis of nanorods.[7-9] Nevertheless, two-dimensional heterogeneous nanocrystals show unique properties, and there is strong impetus to develop them further and explore their potential in various applications, such as optoelectronic device technology, solar cells, hydrogen generation, and catalytic devices. [4] Third-generation solar cells based on colloidal nanocrystals are now generally considered to have good prospects for significant cuts in cost and improvements in efficiency. Since Kamat et al. first put forward the concept that quantum dotsensitized solar cells (QDSCs) share a similar mechanism to dye-sensitized solar cells, [10] there has been wide replacement of organic dyes with quantum dots, leading to a continuous increase in efficiency. [11][12][13] The performance of nanocrystalbased solar cells has closely followed the development of the colloidal nanocrystals, leading to a variety of colloidal QDSCs. These are mainly of three kinds: i) metal/quantum dots (QDs) with a Schottky junction, [14] ii) polymer/nanocrystals hybrid solar cells, [15, 16] and iii) QDSCs.[17] Furthermore, traditional QDs are being replaced by nanorods; it is anticipated that the much better electron transfer ability of a nanorod will lead to significant improvements of the cells. [15] The development of nanocrystals from three-to two-dimensional may also increase the efficiency of QDSCs by improving the electron injection efficiency, which is moderate owing to the strong intrinsic quantum confinement of the photoexcited electrons and holes. [18,19] In general, the carriers in three-dimensional quantum dots are concentrated mainly in the central part;[20] a logical step for enhancement of the electron injection efficiency would be towards nanocrystals that can reduce the confinement of the carriers. We synthesized a new kind of CdSe nanorods, using CdS as the seed, and applied them to quantum-rod-sens...