DP Chemistry (last assessment 2024)
Question 19M.3.hl.TZ2.b
Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.hl.TZ2.b |
Level | hl | Paper | 3 | Time zone | TZ2 |
Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19M.3.hl.TZ2.b
Semiconductors and light-sensitive dyes are used in photovoltaic cells.
Explain the function of dyes in a dye-sensitized solar cell (DSSC).
[2]
Markscheme
dye absorbs light [✔]
electrons from «excited» dye pass to TiO2/semiconductor/electrolyte/cell
OR
dye undergoes photo-oxidation [✔]
Examiners report
The question on dye-sensitized solar cell invited mixed responses. While most candidates correctly stated that dyes absorb light but several failed to mention that electrons from the excited dye pass to TiO2/semiconductor.
