₋    Fabrication and characterization of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)/graphene quantum dots/ Si nanostructure/gold nanoparticle hybrid solar cells.
₋    Determine the efficiency and explore the solar cell's performance enhancement mechanism in each case of the aforementioned hybrid structure.

-    Theoretical results:
We have investigated the fabrication and properties of solar cells using poly (3,4-ethylene dioxythiophene):poly (styrene sulfonate)/graphene quantum dots/ Si material nanostructured/gold nanoparticles hybrid structure. The influence of some technological conditions on the properties of Si/PEDOT:PSS/GQD/AuNP hybrid solar cells was investigated with the following results.
+ Optimal concentration of GO, AuNP for fabricating hybrid solar cells is determined to be 0.5 %wt. In which, the PCE efficiency of solar cells containing 0.5% GO was 7.61% and that of solar cell containing 0.5% AuNPs was 7.31% greater than that of solar cells.
+ Si nanostructures including nanowires (SiNW), nano holes (SiNH) and nano pyramids (SiNP) have been successfully studied and fabricated by chemical etching method. These structures have an effect on the conversion efficiency of Si/PEDOT:PSS solar cells in which solar cells using SiNW give the highest conversion efficiency of 8.15% which is 40% greater than those used by solar cells using planar Si.
+ The effect of GO size on the performance of the hybrid solar cells. The obtained results show that the performance of SiNW/PEDOT:PSS/GQD structured solar cells can be improved when using the small GQD. In this study, the best conversion efficiency of 9.67% was obtained with the solar cells using GQD with the size of 12 nm.
+ Doubled-walled carbon nano tubes (DWCNT) can be used to enhance the conductivity of electrodes and improve the conversion efficiency of solar cells. Parameters such as Jsc, FF and PCE of hybrid solar cell were increased as using DWCNTs and the PCE was measured to be 10.45%.
+ Using AuNP and GQDs in hybrid structure solar cells allows employing the advantages of both materials. The results showed that the solar cells with improved parameters such as Voc, Jsc and FF simultaneously showed the best conversion efficiency of 10.39% which is nearly 10% and and 7.5% greater than that of solar cells containing only AuNP and GQD, respectively.
-    Applied results:
The research results of the topic are expected to make important contributions to the development of the solar cell industry with the aim of improving efficiency and reducing production costs. Thereby, towards the applicability and development of the clean energy industry using solar cells in the near future.

(a) Experimental setup, (b) plasma generated during the SPE process, (c) raw graphite rods obtained from AA-size battery cores, (d) GO solution and (e) optical images of the two electrodes after the SPE process.

(a) SEM image, (b) AFM image, (c-d) diameter and thickness distribution of GO spectra, (e) FTIR spectrum and (f-g) Raman spectrum of graphite obtained from battery core and GO.

₋    Fabricate Si materials with different structures and studied on the influence of different structural Si materials on the conversion efficiency of solar cells.
₋    AuNP and GQD materials have been fabricated and the study evaluated the effects of materials such as AuNPs and GQD on the photovoltaic conversion capacity of solar cells.

- Scientific papers in referred journals (list):
+ NN Anh, NV Chuc, BH Thang, PV Nhat, NV Hao, DD Phuong, PN Minh, T Subramani, N Fukata, PV Trinh, “Solar Cell Based on Hybrid Structural SiNW/Poly(3,4 ethylenedioxythiophene):Poly(styrenesulfonate)/Graphen”, Global Challenges. 9(4) (2020) 2000010 (IF =4.301).
+ N.V.Hao, N.V. Dang, NN Anh, DH Tung, NV Tu, BH Thang, PN Minh and PV Trinh, “Fast, facile and environmentally friendly approach for preparing high thermal conductivity graphene oxide based nanofluids by solution plasma exfoliation”, Materials Letters 287 (2021) 129316 (IF =3.204).
+ NA Nguyen, VH Nguyen, VN Pham, TTLe, VT Nguyen, VT Pham1Effect of graphene oxide concentration on the properties of silicon nanoholes/poly(3,4-ethylene dioxythiophene): poly(styrene sulfonate)/graphene oxide hybrid solar cells, Advances in Natural Sciences: Nanoscience and Nanotechnology (accepted).
+ PV Trinh, NN Anh, NT Bac, NV Hao, LH Chi, BH Thang, NV Chuc, PN Minh, “Enhancing efficiency of silicon micro-pyramids/poly(3,4-ethylenedioxythiophene) :polystyrensulfonate/gold nanoparticles hybrid solar cells”, Mater Sci Sem Processing (IF =3.085) (submitted)
+ PV Trinh, NN Anh, NT Cham, LT Tu, NV Hao, BH Thang, NV Chuc, CT Thanh, LH Chi, PN Minh, N Fukata, “Enhanced power conversion efficiency of n-Si/PEDOT:PSS hybrid solar cell by employing nanostructured silicon surface modification and gold nanoparticles addition” Journal of Science: Advanced Materials and Devices (IF =3.783) (submitted).
+ NV Hao, NT Bac, NN Anh, PV Trinh, “Fabrication and characterization of micropyramid/poly(3,4-ethylene dioxythiophene):polystyrenesulfonate hybrid solar cell”, The 11 international conference on photonic and applications (ICPA-11), Hoa Binh, Vietnam, 4-7/11/2020
+ NT Châm, NN Anh, LT Tú, BH Thắng, NV Chúc, LH Chi, PN Minh, PV Trình, “Nghiên cứu chế tạo và tính chất của pin mặt trời cấu trúc lai nano Si/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/graphene”, Hội nghị Vật lý Chất rắn và Khoa học Vật liệu Toàn quốc – SPMS 2019. tr. 446–449
+ NN Anh, NT Bắc, NT Châm, NV Hảo, BH Thắng, NV Chúc, PN Minh, PV Trình, “Nghiên cứu chế tạo và tính chất của vật liệu silic cấu trúc nano định hướng ứng dụng cho pin mặt trời cấu trúc lai hiệu suất cao”, Hội nghị Vật lý Chất rắn và Khoa học Vật liệu Toàn quốc – SPMS 2019. tr. 450–454.

- Technological products (describe in details: technical characteristics, place):
+ 20 modul solar cells with the efficiency higher than 5%

- Other products (if applicable): 03 Master students