@article{discovery1539032, title = {Tuning Bandgap of p-Type Cu2Zn(Sn, Ge)(S, Se)4 Semiconductor Thin Films via Aqueous Polymer-Assisted Deposition}, year = {2017}, journal = {ACS Applied Materials \& Interfaces}, number = {2}, month = {January}, pages = {1602--1608}, volume = {9}, note = {This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials \& Interfaces, copyright {\copyright} American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acsami.6b13683.}, url = {http://dx.doi.org/10.1021/acsami.6b13683}, abstract = {Bandgap engineering of kesterite Cu2Zn(Sn, Ge)(S, Se)4 with well-controlled stoichiometric composition plays a critical role in sustainable inorganic photovoltaics. Herein, a cost-effective and reproducible aqueous solution-based polymer-assisted deposition approach is developed to grow p-type Cu2Zn(Sn, Ge)(S, Se)4 thin films with tunable bandgap. The bandgap of Cu2Zn(Sn, Ge)(S, Se)4 thin films can be tuned within the range 1.05-1.95 eV using the aqueous polymer-assisted deposition by accurately controlling the elemental compositions. One of the as-grown Cu2Zn(Sn, Ge)(S, Se)4 thin films exhibits a hall coefficient of +137 cm(3)/C. The resistivity, concentration and carrier mobility of the Cu2ZnSn(S, Se)4 thin film are 3.17 ohm.cm, 4.5 {$\times$} 10(16) cm(-3), and 43 cm(2)/(V.S) at room temperature, respectively. Moreover, the Cu2ZnSn(S, Se)4 thin film when used as an active layer in a solar cell leads to a power conversion efficiency of 3.55\%. The facile growth of Cu2Zn(Sn, Ge)(S, Se)4 thin films in an aqueous system, instead of organic solvents, provides great promise as an environmental-friendly platform to fabricate a variety of single/multi metal chalcogenides for the thin film industry and solution-processed photovoltaic devices.}, issn = {1944-8252}, author = {Yi, Q and Wu, J and Zhao, J and Wang, H and Hu, J and Dai, X and Zou, G}, keywords = {CZTGeSSe, bandgap tunable, polymer-assisted deposition, solar cells, solution processing} }