학술논문

Electrical characterization of Cu composition effects in CdS/CdTe thin-film solar cells with a ZnTe:Cu back contact
Document Type
Conference
Source
2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2 Photovoltaic Specialists Conference (PVSC), Volume 2, 2012 IEEE 38th. :1-5 Jun, 2012
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Photonics and Electrooptics
Power, Energy and Industry Applications
Performance evaluation
Switches
Lead
Admittance
Cadmium
Optical films
Gold
admittance measurement
capacitance-voltage characteristics
CdTe
charge carrier density
contacts
defect
Language
Abstract
We study the effects of Cu composition on the CdTe/ZnTe:Cu back contact and the bulk CdTe. For the back contact, its potential barrier decreases with Cu concentration while its saturation current density increases. For the bulk CdTe, the hole density increases with Cu concentration. We identify a Cu-related deep level at ∼0.55 eV whose concentration is significant when the Cu concentration is high. The device performance, which initially improves with Cu concentration then decreases, reflects the interplay between the positive influences (reducing the back contact potential barrier while increasing the saturation current density of the back contact and hole density in CdTe bulk) and negative influences (increasing deep levels in CdTe) of Cu.