Ordered Nanoscale Heterojunction Architecture for Enhanced Solution‐Based CuInGaS₂ Thin Film Solar Cell Performance

Abstract

Nanopatterned CuInGaS 2 (CIGS) thin films synthesized by a sol-gel-based solution method and a nanoimprint lithography technique to achieve simultaneous photonic and electrical enhancements in thin film solar cell applications are demonstrated. The interdigitated CIGS nanopatterns in adjacent CdS layer form an ordered nanoscale heterojunction of optical contrast to create a light trapping architecture. This architecture concomitantly leads to increased junction area between the p-CIGS/n-CdS interface, and thereby influences effective charge transport. The electron beam induced current and capacitance-voltage characterization further supports the large carrier collection area and small depletion region of the nanopatterned CIGS solar cell devices. This strategic geometry affords localization of incident light inside and between the nanopatterns, where created excitons are easily dissociated, and it leads to the enhanced current generation of absorbed light. Ultimately, this approach improves the efficiency of the nanopatterned CIGS solar cell by 55% compared to its planar counterpart, and offers the possibility of simultaneous management for absorption and charge transport through a nanopatterning process.

Passivation of Interfaces in Thin Film Solar Cells: Understanding the Effects of a Nanostructured Rear Point Contact Layer

“…A good FF value is a sign that the contacting area is well defined. [76][77][78][79][80][81][82] In fact, several approaches have been tested in order to increase the reflection and light scattering properties of the rear contact. [71] For the passivated solar cell, these high values of FF show that the nanopatterned passivation layer in terms of density and spacing design forms an effective contacting area.…”

Morphological–Electrical Property Relation in Cu(In,Ga)(S,Se)2 Solar Cells: Significance of Crystal Grain Growth and Band Grading by Potassium Treatment

“…The precursor Cu‐In‐Ga (CIG) solution is prepared by dissolving copper nitrate hydrate (Cu(NO 3 ) 2 ∙ x H 2 O), indium nitrate hydrate (In(NO 3 ) 3 ∙ x H 2 O), and gallium nitrate hydrate (Ga(NO 3 ) 3 ∙ x H 2 O) in methanol. [ 33–37 ] After casting the CIGO x precursor from a solution, a post chalcogenization comprising selenization and sulfurization was applied. The chalcogenization process with increasing time and temperature is described in Figure S2 in the Supporting Information.…”

“…The details of the CIGS film fabrication steps, including the K layer incorporation, are schematically depicted in Figure S1 in the Supporting Information. [33][34][35][36][37] After casting the CIGO x precursor from a solution, a post chalcogenization comprising selenization and sulfurization was applied. The chalcogenization process with increasing time and temperature is described in Figure S2 in the Supporting Information.…”

Präsident der Gesellschaft Deutscher Chemiker: M. Urmann / Paul‐Karrer‐Medaille: H. Waldmann / KCS–Wiley Young Chemist Award: Y. Lee und D.‐H. Ko

“…Zu seinen Forschungsinteressen zählen optoelektronische und smarte Materialien sowie nanophotonische Hybridsensoren. In Advanced Energy Materials hat er nanogemusterte dünne CuInGaS 2 ‐Filme vorgestellt …”