High-quality inorganic compound semiconductors have been considered as key building blocks for fabricating high efficient optoelectronic devices in terms of light efficiency, device durability, and energy-saving. For example, the brightness of InGaN/GaN light-emitting diodes (LED), which are already superior to those of other light emitters, is still showing drastic improvements in the past decade. Despite these advantages, many high technology optoelectronic devices in the market, such as microdisplays for augmented reality and wearable and flexible mobile/large-scale displays, have shifted to use organic LEDs. This market trend has resulted from strong demands for optoelectronic devices having mechanical flexibility, large-size scalability, and monolithically addressable full-color emissions. Meanwhile, these functions are difficult to realize in the current inorganic semiconductor device geometry. High-quality semiconductors can only be grown on rigid single-crystal substrates. Also, the challenge of multiple color generations arises from the monochromatic nature of LEDs. Accordingly, overcoming these issues would make significant breakthroughs in science and technology as well as contribute to brighter prospects of inorganic optoelectronic devices. In this presentation, the speaker will introduce methods to provide diverse novel functionalities to semiconductor devices by fabricating mixed-dimensional heterostructures.  A device platform comprising of semiconductor heteroepitaxy on the 2D layered materials is proposed for the transferable and flexible inorganic optoelectronics and integrated devices with electronics. Furthermore, mixed-dimensional semiconductor nanostructures and microstructures are fabricated in a single chip for the monolithically addressable full-color light emitters where the color control mechanism is a local strain engineering.