The concept of hydrogel-mediated semiconductor wafer bonding was proposed and demonstrated in this work. The unique property of hydrogels was utilized to simultaneously realize high mechanical stability, electrical conductivity, and optical transparency in semiconductor interfaces. The high applicability of this method for rough surfaces to be bonded was also demonstrated, owing to the soft, deformable interfacial contact agent to be solidified in the bonding process. Furthermore, the bonding experiments were carried out in ambient air at room temperature, which, therefore, provides cost and throughput advantages in device production. In addition, the developed bonding technique was used for demonstrating the fabrication and operation of solar cell devices, with current paths across the bonded interfaces, which verified the method's practical applicability. Our semiconductor bonding and interfacial engineering scheme are expected to open up a pathway for simple, handy, and low-cost, but flexible and high-performance optoelectronic material integration.

A new concept of semiconductor wafer bonding, mediated by optical wavelength conversion materials, is proposed and demonstrated. The fabrication scheme provides simultaneous bond formation and interfacial function generation, leading to efficient device production. Wavelength-converting functionalized semiconductor interfacial engineering is realized by utilizing an adhesive viscous organic matrix with embedded fluorescent particles. The bonding is carried out in ambient air at room temperature and therefore provides a cost advantage with regard to device manufacturing. Distinct wavelength conversion, from ultraviolet into visible, and high mechanical stabilities and electrical conductivities in the bonded interfaces are verified, demonstrating their versatility for practical applications. This bonding and interfacial scheme can improve the performance and structural flexibility of optoelectronic devices, such as solar cells, by allowing the spectral light incidence suitable for each photovoltaic material, and photonic integrated circuits, by delivering the respective preferred frequencies to the optical amplifier, modulator, waveguide, and detector materials.

Semiconductor bonding mediated by a transparent conductive oxide, ZnO, prepared by a simple solution spin‐on process, is presented. The ZnO synthesis, sintering, and bonding processes are realized in a single step, thus providing a highly efficient semiconductor bonding method. The ZnO‐mediated bonds simultaneously exhibit high mechanical stability, electrical conductivity, and optical transparency. The bonding's high tolerance for the roughness of the surfaces to be bonded is also demonstrated, due to the soft, deformable interfacial contact agent that is solidified in the bonding process, in contrast to direct bonding and bonding mediated by solid‐state materials. Furthermore, the fabrication and operation of solar‐cell devices are demonstrated using the developed ZnO‐mediated bonding technique, with current paths across the bonded interfaces, thus verifying the practical applicability of the bonding scheme. The developed ZnO‐mediated bonding scheme leads to low‐cost, high‐performance heterostructured optoelectronic device fabrication and integration.

A semiconductor bonding technique that is mediated by graphene quantum dots is proposed and demonstrated. The mechanical stability, electrical conductivity, and optical activity in the bonded interfaces are experimentally verified. First, the bonding scheme can be used for the formation of double heterostructures with a core material of graphene quantum dots. The Si/graphene quantum dots/Si double heterostructures fabricated in this study can constitute a new basis for next-generation nanophotonic devices with high photon and carrier confinements, earth abundance, environmental friendliness, and excellent optical and electrical controllability via silicon clads. Second, the bonding mediated by the graphene quantum dots can be used as an optical-wavelength-converting semiconductor interface, as experimentally demonstrated in this study. The proposed fabrication method simultaneously realizes bond formation and interfacial function generation and, thereby, can lead to efficient device production. Our bonding scheme might improve the performance of optoelectronic devices, for example, by allowing spectral light incidence suitable for each photovoltaic material in multijunction solar cells and by delivering preferred frequencies to the optical transceiver components in photonic integrated circuits.

We propose and experimentally demonstrate a novel concept of semiconductor wafer bonding that simultaneously realizes bond formation and solar cell implementation. Firstly, a semiconductor bonding technique mediated by poly(3,4-ethylenedioxythiophene)—poly(styrenesulfonate) (PEDOT:PSS) is developed. By utilizing the PEDOT:PSS-mediated bonding, we subsequently fabricate an InP/Si heterostructure. The PEDOT:PSS/Si heterojunction derivatively formed at the bonded interface is then demonstrated to operate as a photovoltaic device. The prepared InP/PEDOT:PSS/Si heterostructure can thus be regarded as a prototype architecture representing an intermediate section of a multijunction solar cell with a built-in subcell. Our facile semiconductor bonding scheme mediated by functional agents could lead to low-cost, high-throughput production of high-efficiency multijunction solar cells.